SQLite

CC = @CC@
CFLAGS = @CPPFLAGS@ @CFLAGS@
TCC = ${CC} ${CFLAGS} -I. -I${TOP}/src -I${TOP}/ext/rtree -I${TOP}/ext/icu
TCC += -I${TOP}/ext/fts3 -I${TOP}/ext/async -I${TOP}/ext/session
TCC += -I${TOP}/ext/userauth

# Define this for the autoconf-based build, so that the code knows it can
# include the generated config.h
# include the generated sqlite_cfg.h
#
TCC += -D_HAVE_SQLITE_CONFIG_H -DBUILD_sqlite

# Define -DNDEBUG to compile without debugging (i.e., for production usage)
# Omitting the define will cause extra debugging code to be inserted and
# includes extra comments when "EXPLAIN stmt" is used.
#

         fts3_unicode.lo fts3_unicode2.lo fts3_write.lo \
	 fts5.lo \
         func.lo global.lo hash.lo \
         icu.lo insert.lo json.lo legacy.lo loadext.lo \
         main.lo malloc.lo mem0.lo mem1.lo mem2.lo mem3.lo mem5.lo \
         memdb.lo memjournal.lo \
         mutex.lo mutex_noop.lo mutex_unix.lo mutex_w32.lo \
         notify.lo opcodes.lo os.lo os_unix.lo os_win.lo \
         notify.lo opcodes.lo os.lo os_kv.lo os_unix.lo os_win.lo \
         pager.lo parse.lo pcache.lo pcache1.lo pragma.lo prepare.lo printf.lo \
         random.lo resolve.lo rowset.lo rtree.lo \
         sqlite3session.lo select.lo sqlite3rbu.lo status.lo stmt.lo \
         table.lo threads.lo tokenize.lo treeview.lo trigger.lo \
         update.lo userauth.lo upsert.lo util.lo vacuum.lo \
         vdbe.lo vdbeapi.lo vdbeaux.lo vdbeblob.lo vdbemem.lo vdbesort.lo \
         vdbetrace.lo vdbevtab.lo \

  $(TOP)/src/mutex_unix.c \
  $(TOP)/src/mutex_w32.c \
  $(TOP)/src/notify.c \
  $(TOP)/src/os.c \
  $(TOP)/src/os.h \
  $(TOP)/src/os_common.h \
  $(TOP)/src/os_setup.h \
  $(TOP)/src/os_kv.c \
  $(TOP)/src/os_unix.c \
  $(TOP)/src/os_win.c \
  $(TOP)/src/os_win.h \
  $(TOP)/src/pager.c \
  $(TOP)/src/pager.h \
  $(TOP)/src/parse.y \
  $(TOP)/src/pcache.c \

#
SRC += \
  keywordhash.h \
  opcodes.c \
  opcodes.h \
  parse.c \
  parse.h \
  config.h \
  sqlite_cfg.h \
  shell.c \
  sqlite3.h

# Source code to the test files.
#
TESTSRC = \
  $(TOP)/src/test1.c \

  $(TOP)/src/test_vfs.c \
  $(TOP)/src/test_windirent.c \
  $(TOP)/src/test_window.c \
  $(TOP)/src/test_wsd.c       \
  $(TOP)/ext/fts3/fts3_term.c \
  $(TOP)/ext/fts3/fts3_test.c  \
  $(TOP)/ext/session/test_session.c \
  $(TOP)/ext/recover/sqlite3recover.c \
  $(TOP)/ext/session/sqlite3changebatch.c \
  $(TOP)/ext/recover/dbdata.c \
  $(TOP)/ext/recover/test_recover.c \
  $(TOP)/ext/rbu/test_rbu.c 

# Statically linked extensions
#
TESTSRC += \
  $(TOP)/ext/expert/sqlite3expert.c \
  $(TOP)/ext/expert/test_expert.c \

  $(TOP)/src/func.c \
  $(TOP)/src/global.c \
  $(TOP)/src/insert.c \
  $(TOP)/src/wal.c \
  $(TOP)/src/main.c \
  $(TOP)/src/mem5.c \
  $(TOP)/src/os.c \
  $(TOP)/src/os_kv.c \
  $(TOP)/src/os_unix.c \
  $(TOP)/src/os_win.c \
  $(TOP)/src/pager.c \
  $(TOP)/src/pragma.c \
  $(TOP)/src/prepare.c \
  $(TOP)/src/printf.c \
  $(TOP)/src/random.c \

  $(TOP)/ext/fts3/fts3.c \
  $(TOP)/ext/fts3/fts3_aux.c \
  $(TOP)/ext/fts3/fts3_expr.c \
  $(TOP)/ext/fts3/fts3_term.c \
  $(TOP)/ext/fts3/fts3_tokenizer.c \
  $(TOP)/ext/fts3/fts3_write.c \
  $(TOP)/ext/async/sqlite3async.c \
  $(TOP)/ext/misc/stmt.c \
  $(TOP)/ext/session/sqlite3session.c \
  $(TOP)/ext/session/test_session.c \
  $(TOP)/ext/misc/stmt.c \
  fts5.c

# Header files used by all library source files.
#
HDR = \
   $(TOP)/src/btree.h \
   $(TOP)/src/btreeInt.h \

   $(TOP)/src/sqlite3ext.h \
   $(TOP)/src/sqliteInt.h  \
   $(TOP)/src/sqliteLimit.h \
   $(TOP)/src/vdbe.h \
   $(TOP)/src/vdbeInt.h \
   $(TOP)/src/vxworks.h \
   $(TOP)/src/whereInt.h \
   config.h
   sqlite_cfg.h

# Header files used by extensions
#
EXTHDR += \
  $(TOP)/ext/fts1/fts1.h \
  $(TOP)/ext/fts1/fts1_hash.h \
  $(TOP)/ext/fts1/fts1_tokenizer.h

SHELL_OPT += -DSQLITE_ENABLE_UNKNOWN_SQL_FUNCTION
SHELL_OPT += -DSQLITE_ENABLE_STMTVTAB
SHELL_OPT += -DSQLITE_ENABLE_DBPAGE_VTAB
SHELL_OPT += -DSQLITE_ENABLE_DBSTAT_VTAB
SHELL_OPT += -DSQLITE_ENABLE_BYTECODE_VTAB
SHELL_OPT += -DSQLITE_ENABLE_OFFSET_SQL_FUNC
FUZZERSHELL_OPT = 
FUZZCHECK_OPT += -I$(TOP)/test
FUZZCHECK_OPT += -I$(TOP)/ext/recover
FUZZCHECK_OPT += -DSQLITE_OMIT_LOAD_EXTENSION
FUZZCHECK_OPT = -DSQLITE_ENABLE_MEMSYS5 -DSQLITE_OSS_FUZZ
FUZZCHECK_OPT += -DSQLITE_ENABLE_MEMSYS5 -DSQLITE_OSS_FUZZ
FUZZCHECK_OPT += -DSQLITE_MAX_MEMORY=50000000
FUZZCHECK_OPT += -DSQLITE_PRINTF_PRECISION_LIMIT=1000
FUZZCHECK_OPT += -DSQLITE_ENABLE_FTS4
FUZZCHECK_OPT += -DSQLITE_ENABLE_FTS3_PARENTHESIS
FUZZCHECK_OPT += -DSQLITE_ENABLE_FTS5
FUZZCHECK_OPT += -DSQLITE_ENABLE_RTREE
FUZZCHECK_OPT += -DSQLITE_ENABLE_GEOPOLY
FUZZCHECK_OPT += -DSQLITE_ENABLE_DBSTAT_VTAB
FUZZCHECK_OPT += -DSQLITE_ENABLE_BYTECODE_VTAB
FUZZCHECK_SRC += $(TOP)/test/fuzzcheck.c
FUZZCHECK_SRC += $(TOP)/test/ossfuzz.c
FUZZCHECK_SRC = $(TOP)/test/fuzzcheck.c $(TOP)/test/ossfuzz.c $(TOP)/test/fuzzinvariants.c
FUZZCHECK_SRC += $(TOP)/test/fuzzinvariants.c
FUZZCHECK_SRC += $(TOP)/ext/recover/dbdata.c
FUZZCHECK_SRC += $(TOP)/ext/recover/sqlite3recover.c
FUZZCHECK_SRC += $(TOP)/test/vt02.c
DBFUZZ_OPT =
ST_OPT = -DSQLITE_OS_KV_OPTIONAL

# This is the default Makefile target.  The objects listed here
# are what get build when you type just "make" with no arguments.
#
all:	sqlite3.h libsqlite3.la sqlite3$(TEXE) $(HAVE_TCL:1=libtclsqlite3.la)

Makefile: $(TOP)/Makefile.in

sourcetest:	srcck1$(BEXE) sqlite3.c
	./srcck1 sqlite3.c

fuzzershell$(TEXE):	$(TOP)/tool/fuzzershell.c sqlite3.c sqlite3.h
	$(LTLINK) -o $@ $(FUZZERSHELL_OPT) \
	  $(TOP)/tool/fuzzershell.c sqlite3.c $(TLIBS)

fuzzcheck$(TEXE):	$(FUZZCHECK_SRC) sqlite3.c sqlite3.h
fuzzcheck$(TEXE):	$(FUZZCHECK_SRC) sqlite3.c sqlite3.h $(FUZZCHECK_DEP)
	$(LTLINK) -o $@ $(FUZZCHECK_OPT) $(FUZZCHECK_SRC) sqlite3.c $(TLIBS)

ossshell$(TEXE):	$(TOP)/test/ossfuzz.c $(TOP)/test/ossshell.c sqlite3.c sqlite3.h
	$(LTLINK) -o $@ $(FUZZCHECK_OPT) $(TOP)/test/ossshell.c \
             $(TOP)/test/ossfuzz.c sqlite3.c $(TLIBS)

sessionfuzz$(TEXE):	$(TOP)/test/sessionfuzz.c sqlite3.c sqlite3.h

pcache1.lo:	$(TOP)/src/pcache1.c $(HDR) $(TOP)/src/pcache.h
	$(LTCOMPILE) $(TEMP_STORE) -c $(TOP)/src/pcache1.c

os.lo:	$(TOP)/src/os.c $(HDR)
	$(LTCOMPILE) $(TEMP_STORE) -c $(TOP)/src/os.c

os_kv.lo:	$(TOP)/src/os_kv.c $(HDR)
	$(LTCOMPILE) $(TEMP_STORE) -c $(TOP)/src/os_kv.c

os_unix.lo:	$(TOP)/src/os_unix.c $(HDR)
	$(LTCOMPILE) $(TEMP_STORE) -c $(TOP)/src/os_unix.c

os_win.lo:	$(TOP)/src/os_win.c $(HDR)
	$(LTCOMPILE) $(TEMP_STORE) -c $(TOP)/src/os_win.c

pragma.lo:	$(TOP)/src/pragma.c $(HDR)

	$(TOP)/ext/misc/shathree.c \
	$(TOP)/ext/misc/sqlar.c \
        $(TOP)/ext/misc/uint.c \
	$(TOP)/ext/expert/sqlite3expert.c \
	$(TOP)/ext/expert/sqlite3expert.h \
	$(TOP)/ext/misc/zipfile.c \
	$(TOP)/ext/misc/memtrace.c \
	$(TOP)/ext/recover/dbdata.c \
	$(TOP)/ext/recover/sqlite3recover.c \
	$(TOP)/ext/recover/sqlite3recover.h \
        $(TOP)/src/test_windirent.c

shell.c:	$(SHELL_SRC) $(TOP)/tool/mkshellc.tcl
	$(TCLSH_CMD) $(TOP)/tool/mkshellc.tcl >shell.c

LogEst$(TEXE):	$(TOP)/tool/logest.c sqlite3.h
	$(LTLINK) -I. -o $@ $(TOP)/tool/logest.c

wordcount$(TEXE):	$(TOP)/test/wordcount.c sqlite3.lo
	$(LTLINK) -o $@ $(TOP)/test/wordcount.c sqlite3.lo $(TLIBS)

speedtest1$(TEXE):	$(TOP)/test/speedtest1.c sqlite3.c
speedtest1$(TEXE):	$(TOP)/test/speedtest1.c sqlite3.c Makefile
	$(LTLINK) $(ST_OPT) -o $@ $(TOP)/test/speedtest1.c sqlite3.c $(TLIBS)

startup$(TEXE):	$(TOP)/test/startup.c sqlite3.c
	$(CC) -Os -g -DSQLITE_THREADSAFE=0 -o $@ $(TOP)/test/startup.c sqlite3.c $(TLIBS)

KV_OPT += -DSQLITE_DIRECT_OVERFLOW_READ

	rm -f fuzzcheck fuzzcheck.exe
	rm -f sqldiff sqldiff.exe
	rm -f dbhash dbhash.exe
	rm -f fts5.* fts5parse.*
	rm -f threadtest5

distclean:	clean
	rm -f config.h config.log config.status libtool Makefile sqlite3.pc \
	rm -f sqlite_cfg.h config.log config.status libtool Makefile sqlite3.pc \
		$(TESTPROGS)

#
# Windows section
#
dll: sqlite3.dll

REAL_LIBOBJ = $(LIBOBJ:%.lo=.libs/%.o)

$(REAL_LIBOBJ): $(LIBOBJ)

sqlite3.def: $(REAL_LIBOBJ)
	echo 'EXPORTS' >sqlite3.def
	nm $(REAL_LIBOBJ) | grep ' T ' | grep ' _sqlite3_' \
		| sed 's/^.* _//' >>sqlite3.def

sqlite3.dll: $(REAL_LIBOBJ) sqlite3.def
	$(TCC) -shared -o $@ sqlite3.def \
		-Wl,"--strip-all" $(REAL_LIBOBJ)


#
#
# fiddle/wasm section
# Fiddle app
#
# Maintenance reminder: we can/should move this into the wasm-specific
# GNU Make makefile, but we currently need it here for access to
# $(SHELL_OPT). The rest of the wasm-related bits are handled via GNU
# Make in ext/wasm/...
#
wasm_dir = ext/wasm
wasm_dir_abs = $(TOP)/ext/wasm
# ^^^ some emcc opts require absolute paths
fiddle_dir = $(wasm_dir)/fiddle
fiddle_dir_abs = $(TOP)/$(fiddle_dir)
fiddle_module_js = $(fiddle_dir)/fiddle-module.js
#emcc_opt = -O0
#emcc_opt = -O1
#emcc_opt = -O2
#emcc_opt = -O3
emcc_opt = -Oz
emcc_flags = $(emcc_opt) \
        -sALLOW_TABLE_GROWTH \
        -sABORTING_MALLOC \
        -sSTRICT_JS \
        -sENVIRONMENT=web \
        -sMODULARIZE \
        -sEXPORTED_RUNTIME_METHODS=@$(wasm_dir_abs)/EXPORTED_RUNTIME_METHODS.fiddle \
        -sDYNAMIC_EXECUTION=0 \
        --minify 0 \
        -I. $(SHELL_OPT) \
        -DSQLITE_THREADSAFE=0 -DSQLITE_OMIT_UTF16 -DSQLITE_OMIT_DEPRECATED
$(fiddle_module_js): Makefile sqlite3.c shell.c \
    $(wasm_dir)/EXPORTED_RUNTIME_METHODS.fiddle \
    $(wasm_dir)/EXPORTED_FUNCTIONS.fiddle
	emcc -o $@ $(emcc_flags) \
        -sEXPORT_NAME=initFiddleModule \
        -sEXPORTED_FUNCTIONS=@$(wasm_dir_abs)/EXPORTED_FUNCTIONS.fiddle \
        -DSQLITE_SHELL_FIDDLE \
        sqlite3.c shell.c
fiddle: sqlite3.c shell.c
	gzip < $@ > $@.gz
	gzip < $(fiddle_dir)/fiddle-module.wasm > $(fiddle_dir)/fiddle-module.wasm.gz
$(fiddle_dir)/fiddle.js.gz: $(fiddle_dir)/fiddle.js
	gzip < $< > $@

	make -C ext/wasm fiddle emcc_opt=-Os
fiddle_generated = $(fiddle_module_js) $(fiddle_module_js).gz \
                   $(fiddle_dir)/fiddle-module.wasm \
                   $(fiddle_dir)/fiddle-module.wasm.gz \
                   $(fiddle_dir)/fiddle.js.gz

clean-fiddle:
	rm -f $(fiddle_generated)
clean: clean-fiddle
fiddle: $(fiddle_module_js) $(fiddle_dir)/fiddle.js.gz
wasm: fiddle
########################################################################
# Explanation of the emcc build flags follows. Full docs for these can
# be found at:
#
#  https://github.com/emscripten-core/emscripten/blob/main/src/settings.js
#
# -sENVIRONMENT=web: elides bootstrap code related to non-web JS
#  environments like node.js. Removing this makes the output a tiny
#  tick larger but hypothetically makes it more portable to
#  non-browser JS environments.
#
# -sMODULARIZE: changes how the generated code is structured to avoid
#  declaring a global Module object and instead installing a function
#  which loads and initializes the module. The function is named...
#
# -sEXPORT_NAME=jsFunctionName (see -sMODULARIZE)
#
# -sEXPORTED_RUNTIME_METHODS=@/absolute/path/to/file: a file
#  containing a list of emscripten-supplied APIs, one per line, which
#  must be exported into the generated JS. Must be an absolute path!
#
# -sEXPORTED_FUNCTIONS=@/absolute/path/to/file: a file containing a
#  list of C functions, one per line, which must be exported via wasm
#  so they're visible to JS. C symbols names in that file must all
#  start with an underscore for reasons known only to the emcc
#  developers. e.g., _sqlite3_open_v2 and _sqlite3_finalize. Must be
#  an absolute path!
#
# -sSTRICT_JS ensures that the emitted JS code includes the 'use
#  strict' option. Note that -sSTRICT is more broadly-scoped and
#  results in build errors.
#
# -sALLOW_TABLE_GROWTH is required for (at a minimum) the UDF-binding
#  feature. Without it, JS functions cannot be made to proxy C-side
#  callbacks.
#
# -sABORTING_MALLOC causes the JS-bound _malloc() to abort rather than
#  return 0 on OOM. If set to 0 then all code which uses _malloc()
#  must, just like in C, check the result before using it, else
#  they're likely to corrupt the JS/WASM heap by writing to its
#  address of 0. It is, as of this writing, enabled in Emscripten by
#  default but we enable it explicitly in case that default changes.
#
# -sDYNAMIC_EXECUTION=0 disables eval() and the Function constructor.
#  If the build runs without these, it's preferable to use this flag
#  because certain execution environments disallow those constructs.
#  This flag is not strictly necessary, however.
#
# -sWASM_BIGINT is UNTESTED but "should" allow the int64-using C APIs
#  to work with JS/wasm, insofar as the JS environment supports the
#  BigInt type. That support requires an extremely recent browser:
#  Safari didn't get that support until late 2020.
#
# --no-entry: for compiling library code with no main(). If this is
#  not supplied and the code has a main(), it is called as part of the
#  module init process. Note that main() is #if'd out of shell.c
#  (renamed) when building in wasm mode.
#
# --pre-js/--post-js=FILE relative or absolute paths to JS files to
#  prepend/append to the emcc-generated bootstrapping JS. It's
#  easier/faster to develop with separate JS files (reduces rebuilding
#  requirements) but certain configurations, namely -sMODULARIZE, may
#  require using at least a --pre-js file. They can be used
#  individually and need not be paired.
#
# -O0..-O3 and -Oz: optimization levels affect not only C-style
#  optimization but whether or not the resulting generated JS code
#  gets minified. -O0 compiles _much_ more quickly than -O3 or -Oz,
#  and doesn't minimize any JS code, so is recommended for
#  development. -O3 or -Oz are recommended for deployment, but
#  primarily because -Oz will shrink the wasm file notably. JS-side
#  minification makes little difference in terms of overall
#  distributable size.
#
# --minify 0: disables minification of the generated JS code,
#  regardless of optimization level. Minification of the JS has
#  minimal overall effect in the larger scheme of things and results
#  in JS files which can neither be edited nor viewed as text files in
#  Fossil (which flags them as binary because of their extreme line
#  lengths). Interestingly, whether or not the comments in the
#  generated JS file get stripped is unaffected by this setting and
#  depends entirely on the optimization level. Higher optimization
#  levels reduce the size of the JS considerably even without
#  minification.
#
########################################################################

         fts3_tokenize_vtab.lo fts3_unicode.lo fts3_unicode2.lo fts3_write.lo \
         fts5.lo \
         func.lo global.lo hash.lo \
         icu.lo insert.lo json.lo legacy.lo loadext.lo \
         main.lo malloc.lo mem0.lo mem1.lo mem2.lo mem3.lo mem5.lo \
         memdb.lo memjournal.lo \
         mutex.lo mutex_noop.lo mutex_unix.lo mutex_w32.lo \
         notify.lo opcodes.lo os.lo os_unix.lo os_win.lo \
         notify.lo opcodes.lo os.lo os_kv.lo os_unix.lo os_win.lo \
         pager.lo pcache.lo pcache1.lo pragma.lo prepare.lo printf.lo \
         random.lo resolve.lo rowset.lo rtree.lo \
         sqlite3session.lo select.lo sqlite3rbu.lo status.lo stmt.lo \
         table.lo threads.lo tokenize.lo treeview.lo trigger.lo \
         update.lo upsert.lo util.lo vacuum.lo \
         vdbeapi.lo vdbeaux.lo vdbeblob.lo vdbemem.lo vdbesort.lo \
         vdbetrace.lo vdbevtab.lo wal.lo walker.lo where.lo wherecode.lo \

  $(TOP)\src\memjournal.c \
  $(TOP)\src\mutex.c \
  $(TOP)\src\mutex_noop.c \
  $(TOP)\src\mutex_unix.c \
  $(TOP)\src\mutex_w32.c \
  $(TOP)\src\notify.c \
  $(TOP)\src\os.c \
  $(TOP)\src\os_kv.c \
  $(TOP)\src\os_unix.c \
  $(TOP)\src\os_win.c

# Core source code files, part 2.
#
SRC01 = \
  $(TOP)\src\pager.c \

  $(TOP)\ext\misc\remember.c \
  $(TOP)\ext\misc\series.c \
  $(TOP)\ext\misc\spellfix.c \
  $(TOP)\ext\misc\totype.c \
  $(TOP)\ext\misc\unionvtab.c \
  $(TOP)\ext\misc\wholenumber.c \
  $(TOP)\ext\rtree\test_rtreedoc.c \
  $(TOP)\ext\recover\sqlite3recover.c \
  $(TOP)\ext\recover\test_recover.c \
  $(TOP)\ext\recover\dbdata.c \
  fts5.c

# If use of zlib is enabled, add the "zipfile.c" source file.
#
!IF $(USE_ZLIB)!=0
TESTEXT = $(TESTEXT) $(TOP)\ext\misc\zipfile.c
!ENDIF

!ENDIF

# <<mark>>
# Extra compiler options for various test tools.
#
MPTESTER_COMPILE_OPTS = -DSQLITE_ENABLE_FTS5
FUZZERSHELL_COMPILE_OPTS =
FUZZCHECK_OPTS = $(FUZZCHECK_OPTS) -I$(TOP)\test -I$(TOP)\ext\recover
FUZZCHECK_OPTS = $(FUZZCHECK_OPTS) -DSQLITE_ENABLE_MEMSYS5
FUZZCHECK_OPTS = $(FUZZCHECK_OPTS) -DSQLITE_OSS_FUZZ
FUZZCHECK_OPTS = $(FUZZCHECK_OPTS) -DSQLITE_MAX_MEMORY=50000000
FUZZCHECK_OPTS = -DSQLITE_ENABLE_MEMSYS5 -DSQLITE_OSS_FUZZ -DSQLITE_MAX_MEMORY=50000000 -DSQLITE_PRINTF_PRECISION_LIMIT=1000
FUZZCHECK_OPTS = $(FUZZCHECK_OPTS) -DSQLITE_PRINTF_PRECISION_LIMIT=1000
FUZZCHECK_OPTS = $(FUZZCHECK_OPTS) -DSQLITE_OMIT_LOAD_EXTENSION
FUZZCHECK_OPTS = $(FUZZCHECK_OPTS) -DSQLITE_ENABLE_FTS4
FUZZCHECK_OPTS = $(FUZZCHECK_OPTS) -DSQLITE_ENABLE_FTS5
FUZZCHECK_OPTS = $(FUZZCHECK_OPTS) -DSQLITE_ENABLE_RTREE
FUZZCHECK_OPTS = $(FUZZCHECK_OPTS) -DSQLITE_ENABLE_GEOPOLY
FUZZCHECK_OPTS = $(FUZZCHECK_OPTS) -DSQLITE_ENABLE_DBSTAT_VTAB
FUZZCHECK_OPTS = $(FUZZCHECK_OPTS) -DSQLITE_ENABLE_BYTECODE_VTAB
FUZZCHECK_SRC = $(FUZZCHECK_SRC) $(TOP)\test\fuzzcheck.c
FUZZCHECK_SRC = $(FUZZCHECK_SRC) $(TOP)\test\ossfuzz.c
FUZZCHECK_SRC = $(FUZZCHECK_SRC) $(TOP)\test\fuzzinvariants.c
FUZZCHECK_SRC = $(FUZZCHECK_SRC) $(TOP)\test\vt02.c
FUZZCHECK_SRC = $(FUZZCHECK_SRC) $(TOP)\ext\recover\dbdata.c
FUZZCHECK_SRC = $(FUZZCHECK_SRC) $(TOP)\ext\recover\sqlite3recover.c

FUZZCHECK_SRC = $(TOP)\test\fuzzcheck.c $(TOP)\test\ossfuzz.c $(TOP)\test\fuzzinvariants.c
OSSSHELL_SRC = $(TOP)\test\ossshell.c $(TOP)\test\ossfuzz.c
DBFUZZ_COMPILE_OPTS = -DSQLITE_THREADSAFE=0 -DSQLITE_OMIT_LOAD_EXTENSION
KV_COMPILE_OPTS = -DSQLITE_THREADSAFE=0 -DSQLITE_DIRECT_OVERFLOW_READ
ST_COMPILE_OPTS = -DSQLITE_THREADSAFE=0

# Standard options to testfixture.
#

pcache1.lo:	$(TOP)\src\pcache1.c $(HDR) $(TOP)\src\pcache.h
	$(LTCOMPILE) $(CORE_COMPILE_OPTS) -c $(TOP)\src\pcache1.c

os.lo:	$(TOP)\src\os.c $(HDR)
	$(LTCOMPILE) $(CORE_COMPILE_OPTS) -c $(TOP)\src\os.c

os_kv.lo:	$(TOP)\src\os_kv.c $(HDR)
	$(LTCOMPILE) $(CORE_COMPILE_OPTS) -c $(TOP)\src\os_kv.c

os_unix.lo:	$(TOP)\src\os_unix.c $(HDR)
	$(LTCOMPILE) $(CORE_COMPILE_OPTS) -c $(TOP)\src\os_unix.c

os_win.lo:	$(TOP)\src\os_win.c $(HDR)
	$(LTCOMPILE) $(CORE_COMPILE_OPTS) -c $(TOP)\src\os_win.c

pragma.lo:	$(TOP)\src\pragma.c $(HDR)

	$(TOP)\ext\misc\regexp.c \
	$(TOP)\ext\misc\series.c \
	$(TOP)\ext\misc\shathree.c \
	$(TOP)\ext\misc\uint.c \
	$(TOP)\ext\expert\sqlite3expert.c \
	$(TOP)\ext\expert\sqlite3expert.h \
	$(TOP)\ext\misc\memtrace.c \
	$(TOP)/ext/recover/dbdata.c \
	$(TOP)/ext/recover/sqlite3recover.c \
	$(TOP)/ext/recover/sqlite3recover.h \
	$(TOP)\src\test_windirent.c

# If use of zlib is enabled, add the "zipfile.c" source file.
#
!IF $(USE_ZLIB)!=0
SHELL_SRC = $(SHELL_SRC) $(TOP)\ext\misc\sqlar.c
SHELL_SRC = $(SHELL_SRC) $(TOP)\ext\misc\zipfile.c

/* config.h.in.  Generated from configure.ac by autoheader.  */

/* Define to 1 if you have the <dlfcn.h> header file. */
#undef HAVE_DLFCN_H

/* Define to 1 if you have the `fdatasync' function. */
#undef HAVE_FDATASYNC

/* Define to 1 if you have the `gmtime_r' function. */
#undef HAVE_GMTIME_R

/* Define to 1 if the system has the type `int16_t'. */
#undef HAVE_INT16_T

/* Define to 1 if the system has the type `int32_t'. */
#undef HAVE_INT32_T

/* Define to 1 if the system has the type `int64_t'. */
#undef HAVE_INT64_T

/* Define to 1 if the system has the type `int8_t'. */
#undef HAVE_INT8_T

/* Define to 1 if the system has the type `intptr_t'. */
#undef HAVE_INTPTR_T

/* Define to 1 if you have the <inttypes.h> header file. */
#undef HAVE_INTTYPES_H

/* Define to 1 if you have the `isnan' function. */
#undef HAVE_ISNAN

/* Define to 1 if you have the `localtime_r' function. */
#undef HAVE_LOCALTIME_R

/* Define to 1 if you have the `localtime_s' function. */
#undef HAVE_LOCALTIME_S

/* Define to 1 if you have the <malloc.h> header file. */
#undef HAVE_MALLOC_H

/* Define to 1 if you have the `malloc_usable_size' function. */
#undef HAVE_MALLOC_USABLE_SIZE

/* Define to 1 if you have the <memory.h> header file. */
#undef HAVE_MEMORY_H

/* Define to 1 if you have the pread() function. */
#undef HAVE_PREAD

/* Define to 1 if you have the pread64() function. */
#undef HAVE_PREAD64

/* Define to 1 if you have the pwrite() function. */
#undef HAVE_PWRITE

/* Define to 1 if you have the pwrite64() function. */
#undef HAVE_PWRITE64

/* Define to 1 if you have the <stdint.h> header file. */
#undef HAVE_STDINT_H

/* Define to 1 if you have the <stdlib.h> header file. */
#undef HAVE_STDLIB_H

/* Define to 1 if you have the strchrnul() function */
#undef HAVE_STRCHRNUL

/* Define to 1 if you have the <strings.h> header file. */
#undef HAVE_STRINGS_H

/* Define to 1 if you have the <string.h> header file. */
#undef HAVE_STRING_H

/* Define to 1 if you have the <sys/stat.h> header file. */
#undef HAVE_SYS_STAT_H

/* Define to 1 if you have the <sys/types.h> header file. */
#undef HAVE_SYS_TYPES_H

/* Define to 1 if the system has the type `uint16_t'. */
#undef HAVE_UINT16_T

/* Define to 1 if the system has the type `uint32_t'. */
#undef HAVE_UINT32_T

/* Define to 1 if the system has the type `uint64_t'. */
#undef HAVE_UINT64_T

/* Define to 1 if the system has the type `uint8_t'. */
#undef HAVE_UINT8_T

/* Define to 1 if the system has the type `uintptr_t'. */
#undef HAVE_UINTPTR_T

/* Define to 1 if you have the <unistd.h> header file. */
#undef HAVE_UNISTD_H

/* Define to 1 if you have the `usleep' function. */
#undef HAVE_USLEEP

/* Define to 1 if you have the utime() library function. */
#undef HAVE_UTIME

/* Define to the sub-directory in which libtool stores uninstalled libraries.
   */
#undef LT_OBJDIR

/* Define to the address where bug reports for this package should be sent. */
#undef PACKAGE_BUGREPORT

/* Define to the full name of this package. */
#undef PACKAGE_NAME

/* Define to the full name and version of this package. */
#undef PACKAGE_STRING

/* Define to the one symbol short name of this package. */
#undef PACKAGE_TARNAME

/* Define to the version of this package. */
#undef PACKAGE_VERSION

/* Define to 1 if you have the ANSI C header files. */
#undef STDC_HEADERS

/* Number of bits in a file offset, on hosts where this is settable. */
#undef _FILE_OFFSET_BITS

/* Define for large files, on AIX-style hosts. */
#undef _LARGE_FILES

if test "${amalgamation_line_macros}" = "no" ; then
  AMALGAMATION_LINE_MACROS=--linemacros=0
fi


#########
# Output the config header
ac_config_headers="$ac_config_headers config.h"
ac_config_headers="$ac_config_headers sqlite_cfg.h"


#########
# Generate the output files.
#

ac_config_files="$ac_config_files Makefile sqlite3.pc"

cat >>$CONFIG_STATUS <<\_ACEOF || ac_write_fail=1

# Handling of arguments.
for ac_config_target in $ac_config_targets
do
  case $ac_config_target in
    "libtool") CONFIG_COMMANDS="$CONFIG_COMMANDS libtool" ;;
    "config.h") CONFIG_HEADERS="$CONFIG_HEADERS config.h" ;;
    "sqlite_cfg.h") CONFIG_HEADERS="$CONFIG_HEADERS sqlite_cfg.h" ;;
    "Makefile") CONFIG_FILES="$CONFIG_FILES Makefile" ;;
    "sqlite3.pc") CONFIG_FILES="$CONFIG_FILES sqlite3.pc" ;;

  *) as_fn_error $? "invalid argument: \`$ac_config_target'" "$LINENO" 5;;
  esac
done

if test "${amalgamation_line_macros}" = "no" ; then
  AMALGAMATION_LINE_MACROS=--linemacros=0
fi
AC_SUBST(AMALGAMATION_LINE_MACROS)

#########
# Output the config header
AC_CONFIG_HEADERS(config.h)
AC_CONFIG_HEADERS(sqlite_cfg.h)

#########
# Generate the output files.
#
AC_SUBST(BUILD_CFLAGS)
AC_OUTPUT([
Makefile

Begin Concurrent
================

## Overview

Usually, SQLite allows at most one writer to proceed concurrently. The
BEGIN CONCURRENT enhancement allows multiple writers to process write
transactions simultanously if the database is in "wal" or "wal2" mode,
although the system still serializes COMMIT commands.

When a write-transaction is opened with "BEGIN CONCURRENT", actually 
locking the database is deferred until a COMMIT is executed. This means
that any number of transactions started with BEGIN CONCURRENT may proceed
concurrently. The system uses optimistic page-level-locking to prevent
conflicting concurrent transactions from being committed.

When a BEGIN CONCURRENT transaction is committed, the system checks whether 
or not any of the database pages that the transaction has read have been
modified since the BEGIN CONCURRENT was opened. In other words - it asks 
if the transaction being committed operates on a different set of data than
all other concurrently executing transactions. If the answer is "yes, this
transaction did not read or modify any data modified by any concurrent
transaction", then the transaction is committed as normal. Otherwise, if the
transaction does conflict, it cannot be committed and an SQLITE_BUSY_SNAPSHOT
error is returned. At this point, all the client can do is ROLLBACK the
transaction.

If SQLITE_BUSY_SNAPSHOT is returned, messages are output via the sqlite3_log
mechanism indicating the page and table or index on which the conflict
occurred. This can be useful when optimizing concurrency.

## Application Programming Notes

In order to serialize COMMIT processing, SQLite takes a lock on the database
as part of each COMMIT command and releases it before returning. At most one
writer may hold this lock at any one time. If a writer cannot obtain the lock,
it uses SQLite's busy-handler to pause and retry for a while:

  <a href=https://www.sqlite.org/c3ref/busy_handler.html>
      https://www.sqlite.org/c3ref/busy_handler.html
  </a>

If there is significant contention for the writer lock, this mechanism can be
inefficient. In this case it is better for the application to use a mutex or
some other mechanism that supports blocking to ensure that at most one writer
is attempting to COMMIT a BEGIN CONCURRENT transaction at a time. This is
usually easier if all writers are part of the same operating system process.

If all database clients (readers and writers) are located in the same OS
process, and if that OS is a Unix variant, then it can be more efficient to
the built-in VFS "unix-excl" instead of the default "unix". This is because it
uses more efficient locking primitives.

The key to maximizing concurrency using BEGIN CONCURRENT is to ensure that
there are a large number of non-conflicting transactions. In SQLite, each
table and each index is stored as a separate b-tree, each of which is
distributed over a discrete set of database pages. This means that:

  * Two transactions that write to different sets of tables never 
    conflict, and that

  * Two transactions that write to the same tables or indexes only 
    conflict if the values of the keys (either primary keys or indexed 
    rows) are fairly close together. For example, given a large 
    table with the schema:

      <pre>     CREATE TABLE t1(a INTEGER PRIMARY KEY, b BLOB);</pre>

    writing two rows with adjacent values for "a" probably will cause a
    conflict (as the two keys are stored on the same page), but writing two
    rows with vastly different values for "a" will not (as the keys will likly
    be stored on different pages).

Note that, in SQLite, if values are not explicitly supplied for an INTEGER
PRIMARY KEY, as for example in:

>
     INSERT INTO t1(b) VALUES(<blob-value>);

then monotonically increasing values are assigned automatically. This is
terrible for concurrency, as it all but ensures that all new rows are 
added to the same database page. In such situations, it is better to
explicitly assign random values to INTEGER PRIMARY KEY fields.

This problem also comes up for non-WITHOUT ROWID tables that do not have an
explicit INTEGER PRIMARY KEY column. In these cases each table has an implicit
INTEGER PRIMARY KEY column that is assigned increasing values, leading to the
same problem as omitting to assign a value to an explicit INTEGER PRIMARY KEY
column.

For both explicit and implicit INTEGER PRIMARY KEYs, it is possible to have
SQLite assign values at random (instead of the monotonically increasing
values) by writing a row with a rowid equal to the largest possible signed
64-bit integer to the table. For example:

     INSERT INTO t1(a) VALUES(9223372036854775807);

Applications should take care not to malfunction due to the presence of such
rows.

The nature of some types of indexes, for example indexes on timestamp fields,
can also cause problems (as concurrent transactions may assign similar
timestamps that will be stored on the same db page to new records). In these
cases the database schema may need to be rethought to increase the concurrency
provided by page-level-locking.

** to the sqlite3_load_extension() API call.  Then you invoke the
** sqlite3_load_extension() API and shutdown the dummy database
** connection.  All subsequent database connections that are opened
** will include this extension.  For example:
**
**     sqlite3 *db;
**     sqlite3_open(":memory:", &db);
**     sqlite3_load_extention(db, "./cksumvfs");
**     sqlite3_load_extension(db, "./cksumvfs");
**     sqlite3_close(db);
**
** If this extension is compiled with -DSQLITE_CKSUMVFS_STATIC and
** statically linked against the application, initialize it using
** a single API call as follows:
**
**     sqlite3_register_cksumvfs();

/*
** 2019-04-17
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
******************************************************************************
**
** This file contains an implementation of two eponymous virtual tables,
** "sqlite_dbdata" and "sqlite_dbptr". Both modules require that the
** "sqlite_dbpage" eponymous virtual table be available.
**
** SQLITE_DBDATA:
**   sqlite_dbdata is used to extract data directly from a database b-tree
**   page and its associated overflow pages, bypassing the b-tree layer.
**   The table schema is equivalent to:
**
**     CREATE TABLE sqlite_dbdata(
**       pgno INTEGER,
**       cell INTEGER,
**       field INTEGER,
**       value ANY,
**       schema TEXT HIDDEN
**     );
**
**   IMPORTANT: THE VIRTUAL TABLE SCHEMA ABOVE IS SUBJECT TO CHANGE. IN THE
**   FUTURE NEW NON-HIDDEN COLUMNS MAY BE ADDED BETWEEN "value" AND
**   "schema".
**
**   Each page of the database is inspected. If it cannot be interpreted as
**   a b-tree page, or if it is a b-tree page containing 0 entries, the
**   sqlite_dbdata table contains no rows for that page.  Otherwise, the
**   table contains one row for each field in the record associated with
**   each cell on the page. For intkey b-trees, the key value is stored in
**   field -1.
**
**   For example, for the database:
**
**     CREATE TABLE t1(a, b);     -- root page is page 2
**     INSERT INTO t1(rowid, a, b) VALUES(5, 'v', 'five');
**     INSERT INTO t1(rowid, a, b) VALUES(10, 'x', 'ten');
**
**   the sqlite_dbdata table contains, as well as from entries related to 
**   page 1, content equivalent to:
**
**     INSERT INTO sqlite_dbdata(pgno, cell, field, value) VALUES
**         (2, 0, -1, 5     ),
**         (2, 0,  0, 'v'   ),
**         (2, 0,  1, 'five'),
**         (2, 1, -1, 10    ),
**         (2, 1,  0, 'x'   ),
**         (2, 1,  1, 'ten' );
**
**   If database corruption is encountered, this module does not report an
**   error. Instead, it attempts to extract as much data as possible and
**   ignores the corruption.
**
** SQLITE_DBPTR:
**   The sqlite_dbptr table has the following schema:
**
**     CREATE TABLE sqlite_dbptr(
**       pgno INTEGER,
**       child INTEGER,
**       schema TEXT HIDDEN
**     );
**
**   It contains one entry for each b-tree pointer between a parent and
**   child page in the database.
*/
#if !defined(SQLITEINT_H) 
#include "sqlite3ext.h"

typedef unsigned char u8;

#endif
SQLITE_EXTENSION_INIT1
#include <string.h>
#include <assert.h>

#define DBDATA_PADDING_BYTES 100 

typedef struct DbdataTable DbdataTable;
typedef struct DbdataCursor DbdataCursor;

/* Cursor object */
struct DbdataCursor {
  sqlite3_vtab_cursor base;       /* Base class.  Must be first */
  sqlite3_stmt *pStmt;            /* For fetching database pages */

  int iPgno;                      /* Current page number */
  u8 *aPage;                      /* Buffer containing page */
  int nPage;                      /* Size of aPage[] in bytes */
  int nCell;                      /* Number of cells on aPage[] */
  int iCell;                      /* Current cell number */
  int bOnePage;                   /* True to stop after one page */
  int szDb;
  sqlite3_int64 iRowid;

  /* Only for the sqlite_dbdata table */
  u8 *pRec;                       /* Buffer containing current record */
  int nRec;                       /* Size of pRec[] in bytes */
  int nHdr;                       /* Size of header in bytes */
  int iField;                     /* Current field number */
  u8 *pHdrPtr;
  u8 *pPtr;
  
  sqlite3_int64 iIntkey;          /* Integer key value */
};

/* Table object */
struct DbdataTable {
  sqlite3_vtab base;              /* Base class.  Must be first */
  sqlite3 *db;                    /* The database connection */
  sqlite3_stmt *pStmt;            /* For fetching database pages */
  int bPtr;                       /* True for sqlite3_dbptr table */
};

/* Column and schema definitions for sqlite_dbdata */
#define DBDATA_COLUMN_PGNO        0
#define DBDATA_COLUMN_CELL        1
#define DBDATA_COLUMN_FIELD       2
#define DBDATA_COLUMN_VALUE       3
#define DBDATA_COLUMN_SCHEMA      4
#define DBDATA_SCHEMA             \
      "CREATE TABLE x("           \
      "  pgno INTEGER,"           \
      "  cell INTEGER,"           \
      "  field INTEGER,"          \
      "  value ANY,"              \
      "  schema TEXT HIDDEN"      \
      ")"

/* Column and schema definitions for sqlite_dbptr */
#define DBPTR_COLUMN_PGNO         0
#define DBPTR_COLUMN_CHILD        1
#define DBPTR_COLUMN_SCHEMA       2
#define DBPTR_SCHEMA              \
      "CREATE TABLE x("           \
      "  pgno INTEGER,"           \
      "  child INTEGER,"          \
      "  schema TEXT HIDDEN"      \
      ")"

/*
** Connect to an sqlite_dbdata (pAux==0) or sqlite_dbptr (pAux!=0) virtual 
** table.
*/
static int dbdataConnect(
  sqlite3 *db,
  void *pAux,
  int argc, const char *const*argv,
  sqlite3_vtab **ppVtab,
  char **pzErr
){
  DbdataTable *pTab = 0;
  int rc = sqlite3_declare_vtab(db, pAux ? DBPTR_SCHEMA : DBDATA_SCHEMA);

  if( rc==SQLITE_OK ){
    pTab = (DbdataTable*)sqlite3_malloc64(sizeof(DbdataTable));
    if( pTab==0 ){
      rc = SQLITE_NOMEM;
    }else{
      memset(pTab, 0, sizeof(DbdataTable));
      pTab->db = db;
      pTab->bPtr = (pAux!=0);
    }
  }

  *ppVtab = (sqlite3_vtab*)pTab;
  return rc;
}

/*
** Disconnect from or destroy a sqlite_dbdata or sqlite_dbptr virtual table.
*/
static int dbdataDisconnect(sqlite3_vtab *pVtab){
  DbdataTable *pTab = (DbdataTable*)pVtab;
  if( pTab ){
    sqlite3_finalize(pTab->pStmt);
    sqlite3_free(pVtab);
  }
  return SQLITE_OK;
}

/*
** This function interprets two types of constraints:
**
**       schema=?
**       pgno=?
**
** If neither are present, idxNum is set to 0. If schema=? is present,
** the 0x01 bit in idxNum is set. If pgno=? is present, the 0x02 bit
** in idxNum is set.
**
** If both parameters are present, schema is in position 0 and pgno in
** position 1.
*/
static int dbdataBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdx){
  DbdataTable *pTab = (DbdataTable*)tab;
  int i;
  int iSchema = -1;
  int iPgno = -1;
  int colSchema = (pTab->bPtr ? DBPTR_COLUMN_SCHEMA : DBDATA_COLUMN_SCHEMA);

  for(i=0; i<pIdx->nConstraint; i++){
    struct sqlite3_index_constraint *p = &pIdx->aConstraint[i];
    if( p->op==SQLITE_INDEX_CONSTRAINT_EQ ){
      if( p->iColumn==colSchema ){
        if( p->usable==0 ) return SQLITE_CONSTRAINT;
        iSchema = i;
      }
      if( p->iColumn==DBDATA_COLUMN_PGNO && p->usable ){
        iPgno = i;
      }
    }
  }

  if( iSchema>=0 ){
    pIdx->aConstraintUsage[iSchema].argvIndex = 1;
    pIdx->aConstraintUsage[iSchema].omit = 1;
  }
  if( iPgno>=0 ){
    pIdx->aConstraintUsage[iPgno].argvIndex = 1 + (iSchema>=0);
    pIdx->aConstraintUsage[iPgno].omit = 1;
    pIdx->estimatedCost = 100;
    pIdx->estimatedRows =  50;

    if( pTab->bPtr==0 && pIdx->nOrderBy && pIdx->aOrderBy[0].desc==0 ){
      int iCol = pIdx->aOrderBy[0].iColumn;
      if( pIdx->nOrderBy==1 ){
        pIdx->orderByConsumed = (iCol==0 || iCol==1);
      }else if( pIdx->nOrderBy==2 && pIdx->aOrderBy[1].desc==0 && iCol==0 ){
        pIdx->orderByConsumed = (pIdx->aOrderBy[1].iColumn==1);
      }
    }

  }else{
    pIdx->estimatedCost = 100000000;
    pIdx->estimatedRows = 1000000000;
  }
  pIdx->idxNum = (iSchema>=0 ? 0x01 : 0x00) | (iPgno>=0 ? 0x02 : 0x00);
  return SQLITE_OK;
}

/*
** Open a new sqlite_dbdata or sqlite_dbptr cursor.
*/
static int dbdataOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
  DbdataCursor *pCsr;

  pCsr = (DbdataCursor*)sqlite3_malloc64(sizeof(DbdataCursor));
  if( pCsr==0 ){
    return SQLITE_NOMEM;
  }else{
    memset(pCsr, 0, sizeof(DbdataCursor));
    pCsr->base.pVtab = pVTab;
  }

  *ppCursor = (sqlite3_vtab_cursor *)pCsr;
  return SQLITE_OK;
}

/*
** Restore a cursor object to the state it was in when first allocated 
** by dbdataOpen().
*/
static void dbdataResetCursor(DbdataCursor *pCsr){
  DbdataTable *pTab = (DbdataTable*)(pCsr->base.pVtab);
  if( pTab->pStmt==0 ){
    pTab->pStmt = pCsr->pStmt;
  }else{
    sqlite3_finalize(pCsr->pStmt);
  }
  pCsr->pStmt = 0;
  pCsr->iPgno = 1;
  pCsr->iCell = 0;
  pCsr->iField = 0;
  pCsr->bOnePage = 0;
  sqlite3_free(pCsr->aPage);
  sqlite3_free(pCsr->pRec);
  pCsr->pRec = 0;
  pCsr->aPage = 0;
}

/*
** Close an sqlite_dbdata or sqlite_dbptr cursor.
*/
static int dbdataClose(sqlite3_vtab_cursor *pCursor){
  DbdataCursor *pCsr = (DbdataCursor*)pCursor;
  dbdataResetCursor(pCsr);
  sqlite3_free(pCsr);
  return SQLITE_OK;
}

/* 
** Utility methods to decode 16 and 32-bit big-endian unsigned integers. 
*/
static unsigned int get_uint16(unsigned char *a){
  return (a[0]<<8)|a[1];
}
static unsigned int get_uint32(unsigned char *a){
  return ((unsigned int)a[0]<<24)
       | ((unsigned int)a[1]<<16)
       | ((unsigned int)a[2]<<8)
       | ((unsigned int)a[3]);
}

/*
** Load page pgno from the database via the sqlite_dbpage virtual table.
** If successful, set (*ppPage) to point to a buffer containing the page
** data, (*pnPage) to the size of that buffer in bytes and return
** SQLITE_OK. In this case it is the responsibility of the caller to
** eventually free the buffer using sqlite3_free().
**
** Or, if an error occurs, set both (*ppPage) and (*pnPage) to 0 and
** return an SQLite error code.
*/
static int dbdataLoadPage(
  DbdataCursor *pCsr,             /* Cursor object */
  unsigned int pgno,              /* Page number of page to load */
  u8 **ppPage,                    /* OUT: pointer to page buffer */
  int *pnPage                     /* OUT: Size of (*ppPage) in bytes */
){
  int rc2;
  int rc = SQLITE_OK;
  sqlite3_stmt *pStmt = pCsr->pStmt;

  *ppPage = 0;
  *pnPage = 0;
  sqlite3_bind_int64(pStmt, 2, pgno);
  if( SQLITE_ROW==sqlite3_step(pStmt) ){
    int nCopy = sqlite3_column_bytes(pStmt, 0);
    if( nCopy>0 ){
      u8 *pPage;
      pPage = (u8*)sqlite3_malloc64(nCopy + DBDATA_PADDING_BYTES);
      if( pPage==0 ){
        rc = SQLITE_NOMEM;
      }else{
        const u8 *pCopy = sqlite3_column_blob(pStmt, 0);
        memcpy(pPage, pCopy, nCopy);
        memset(&pPage[nCopy], 0, DBDATA_PADDING_BYTES);
      }
      *ppPage = pPage;
      *pnPage = nCopy;
    }
  }
  rc2 = sqlite3_reset(pStmt);
  if( rc==SQLITE_OK ) rc = rc2;

  return rc;
}

/*
** Read a varint.  Put the value in *pVal and return the number of bytes.
*/
static int dbdataGetVarint(const u8 *z, sqlite3_int64 *pVal){
  sqlite3_int64 v = 0;
  int i;
  for(i=0; i<8; i++){
    v = (v<<7) + (z[i]&0x7f);
    if( (z[i]&0x80)==0 ){ *pVal = v; return i+1; }
  }
  v = (v<<8) + (z[i]&0xff);
  *pVal = v;
  return 9;
}

/*
** Return the number of bytes of space used by an SQLite value of type
** eType.
*/
static int dbdataValueBytes(int eType){
  switch( eType ){
    case 0: case 8: case 9:
    case 10: case 11:
      return 0;
    case 1:
      return 1;
    case 2:
      return 2;
    case 3:
      return 3;
    case 4:
      return 4;
    case 5:
      return 6;
    case 6:
    case 7:
      return 8;
    default:
      if( eType>0 ){
        return ((eType-12) / 2);
      }
      return 0;
  }
}

/*
** Load a value of type eType from buffer pData and use it to set the
** result of context object pCtx.
*/
static void dbdataValue(
  sqlite3_context *pCtx, 
  int eType, 
  u8 *pData,
  int nData
){
  if( eType>=0 && dbdataValueBytes(eType)<=nData ){
    switch( eType ){
      case 0: 
      case 10: 
      case 11: 
        sqlite3_result_null(pCtx);
        break;
      
      case 8: 
        sqlite3_result_int(pCtx, 0);
        break;
      case 9:
        sqlite3_result_int(pCtx, 1);
        break;
  
      case 1: case 2: case 3: case 4: case 5: case 6: case 7: {
        sqlite3_uint64 v = (signed char)pData[0];
        pData++;
        switch( eType ){
          case 7:
          case 6:  v = (v<<16) + (pData[0]<<8) + pData[1];  pData += 2;
          case 5:  v = (v<<16) + (pData[0]<<8) + pData[1];  pData += 2;
          case 4:  v = (v<<8) + pData[0];  pData++;
          case 3:  v = (v<<8) + pData[0];  pData++;
          case 2:  v = (v<<8) + pData[0];  pData++;
        }
  
        if( eType==7 ){
          double r;
          memcpy(&r, &v, sizeof(r));
          sqlite3_result_double(pCtx, r);
        }else{
          sqlite3_result_int64(pCtx, (sqlite3_int64)v);
        }
        break;
      }
  
      default: {
        int n = ((eType-12) / 2);
        if( eType % 2 ){
          sqlite3_result_text(pCtx, (const char*)pData, n, SQLITE_TRANSIENT);
        }else{
          sqlite3_result_blob(pCtx, pData, n, SQLITE_TRANSIENT);
        }
      }
    }
  }
}

/*
** Move an sqlite_dbdata or sqlite_dbptr cursor to the next entry.
*/
static int dbdataNext(sqlite3_vtab_cursor *pCursor){
  DbdataCursor *pCsr = (DbdataCursor*)pCursor;
  DbdataTable *pTab = (DbdataTable*)pCursor->pVtab;

  pCsr->iRowid++;
  while( 1 ){
    int rc;
    int iOff = (pCsr->iPgno==1 ? 100 : 0);
    int bNextPage = 0;

    if( pCsr->aPage==0 ){
      while( 1 ){
        if( pCsr->bOnePage==0 && pCsr->iPgno>pCsr->szDb ) return SQLITE_OK;
        rc = dbdataLoadPage(pCsr, pCsr->iPgno, &pCsr->aPage, &pCsr->nPage);
        if( rc!=SQLITE_OK ) return rc;
        if( pCsr->aPage ) break;
        pCsr->iPgno++;
      }
      pCsr->iCell = pTab->bPtr ? -2 : 0;
      pCsr->nCell = get_uint16(&pCsr->aPage[iOff+3]);
    }

    if( pTab->bPtr ){
      if( pCsr->aPage[iOff]!=0x02 && pCsr->aPage[iOff]!=0x05 ){
        pCsr->iCell = pCsr->nCell;
      }
      pCsr->iCell++;
      if( pCsr->iCell>=pCsr->nCell ){
        sqlite3_free(pCsr->aPage);
        pCsr->aPage = 0;
        if( pCsr->bOnePage ) return SQLITE_OK;
        pCsr->iPgno++;
      }else{
        return SQLITE_OK;
      }
    }else{
      /* If there is no record loaded, load it now. */
      if( pCsr->pRec==0 ){
        int bHasRowid = 0;
        int nPointer = 0;
        sqlite3_int64 nPayload = 0;
        sqlite3_int64 nHdr = 0;
        int iHdr;
        int U, X;
        int nLocal;
  
        switch( pCsr->aPage[iOff] ){
          case 0x02:
            nPointer = 4;
            break;
          case 0x0a:
            break;
          case 0x0d:
            bHasRowid = 1;
            break;
          default:
            /* This is not a b-tree page with records on it. Continue. */
            pCsr->iCell = pCsr->nCell;
            break;
        }

        if( pCsr->iCell>=pCsr->nCell ){
          bNextPage = 1;
        }else{
  
          iOff += 8 + nPointer + pCsr->iCell*2;
          if( iOff>pCsr->nPage ){
            bNextPage = 1;
          }else{
            iOff = get_uint16(&pCsr->aPage[iOff]);
          }
    
          /* For an interior node cell, skip past the child-page number */
          iOff += nPointer;
    
          /* Load the "byte of payload including overflow" field */
          if( bNextPage || iOff>pCsr->nPage ){
            bNextPage = 1;
          }else{
            iOff += dbdataGetVarint(&pCsr->aPage[iOff], &nPayload);
          }
    
          /* If this is a leaf intkey cell, load the rowid */
          if( bHasRowid && !bNextPage && iOff<pCsr->nPage ){
            iOff += dbdataGetVarint(&pCsr->aPage[iOff], &pCsr->iIntkey);
          }
    
          /* Figure out how much data to read from the local page */
          U = pCsr->nPage;
          if( bHasRowid ){
            X = U-35;
          }else{
            X = ((U-12)*64/255)-23;
          }
          if( nPayload<=X ){
            nLocal = nPayload;
          }else{
            int M, K;
            M = ((U-12)*32/255)-23;
            K = M+((nPayload-M)%(U-4));
            if( K<=X ){
              nLocal = K;
            }else{
              nLocal = M;
            }
          }

          if( bNextPage || nLocal+iOff>pCsr->nPage ){
            bNextPage = 1;
          }else{

            /* Allocate space for payload. And a bit more to catch small buffer
            ** overruns caused by attempting to read a varint or similar from 
            ** near the end of a corrupt record.  */
            pCsr->pRec = (u8*)sqlite3_malloc64(nPayload+DBDATA_PADDING_BYTES);
            if( pCsr->pRec==0 ) return SQLITE_NOMEM;
            memset(pCsr->pRec, 0, nPayload+DBDATA_PADDING_BYTES);
            pCsr->nRec = nPayload;

            /* Load the nLocal bytes of payload */
            memcpy(pCsr->pRec, &pCsr->aPage[iOff], nLocal);
            iOff += nLocal;

            /* Load content from overflow pages */
            if( nPayload>nLocal ){
              sqlite3_int64 nRem = nPayload - nLocal;
              unsigned int pgnoOvfl = get_uint32(&pCsr->aPage[iOff]);
              while( nRem>0 ){
                u8 *aOvfl = 0;
                int nOvfl = 0;
                int nCopy;
                rc = dbdataLoadPage(pCsr, pgnoOvfl, &aOvfl, &nOvfl);
                assert( rc!=SQLITE_OK || aOvfl==0 || nOvfl==pCsr->nPage );
                if( rc!=SQLITE_OK ) return rc;
                if( aOvfl==0 ) break;

                nCopy = U-4;
                if( nCopy>nRem ) nCopy = nRem;
                memcpy(&pCsr->pRec[nPayload-nRem], &aOvfl[4], nCopy);
                nRem -= nCopy;

                pgnoOvfl = get_uint32(aOvfl);
                sqlite3_free(aOvfl);
              }
            }
    
            iHdr = dbdataGetVarint(pCsr->pRec, &nHdr);
            pCsr->nHdr = nHdr;
            pCsr->pHdrPtr = &pCsr->pRec[iHdr];
            pCsr->pPtr = &pCsr->pRec[pCsr->nHdr];
            pCsr->iField = (bHasRowid ? -1 : 0);
          }
        }
      }else{
        pCsr->iField++;
        if( pCsr->iField>0 ){
          sqlite3_int64 iType;
          if( pCsr->pHdrPtr>&pCsr->pRec[pCsr->nRec] ){
            bNextPage = 1;
          }else{
            pCsr->pHdrPtr += dbdataGetVarint(pCsr->pHdrPtr, &iType);
            pCsr->pPtr += dbdataValueBytes(iType);
          }
        }
      }

      if( bNextPage ){
        sqlite3_free(pCsr->aPage);
        sqlite3_free(pCsr->pRec);
        pCsr->aPage = 0;
        pCsr->pRec = 0;
        if( pCsr->bOnePage ) return SQLITE_OK;
        pCsr->iPgno++;
      }else{
        if( pCsr->iField<0 || pCsr->pHdrPtr<&pCsr->pRec[pCsr->nHdr] ){
          return SQLITE_OK;
        }

        /* Advance to the next cell. The next iteration of the loop will load
        ** the record and so on. */
        sqlite3_free(pCsr->pRec);
        pCsr->pRec = 0;
        pCsr->iCell++;
      }
    }
  }

  assert( !"can't get here" );
  return SQLITE_OK;
}

/* 
** Return true if the cursor is at EOF.
*/
static int dbdataEof(sqlite3_vtab_cursor *pCursor){
  DbdataCursor *pCsr = (DbdataCursor*)pCursor;
  return pCsr->aPage==0;
}

/* 
** Determine the size in pages of database zSchema (where zSchema is
** "main", "temp" or the name of an attached database) and set 
** pCsr->szDb accordingly. If successful, return SQLITE_OK. Otherwise,
** an SQLite error code.
*/
static int dbdataDbsize(DbdataCursor *pCsr, const char *zSchema){
  DbdataTable *pTab = (DbdataTable*)pCsr->base.pVtab;
  char *zSql = 0;
  int rc, rc2;
  sqlite3_stmt *pStmt = 0;

  zSql = sqlite3_mprintf("PRAGMA %Q.page_count", zSchema);
  if( zSql==0 ) return SQLITE_NOMEM;
  rc = sqlite3_prepare_v2(pTab->db, zSql, -1, &pStmt, 0);
  sqlite3_free(zSql);
  if( rc==SQLITE_OK && sqlite3_step(pStmt)==SQLITE_ROW ){
    pCsr->szDb = sqlite3_column_int(pStmt, 0);
  }
  rc2 = sqlite3_finalize(pStmt);
  if( rc==SQLITE_OK ) rc = rc2;
  return rc;
}

/* 
** xFilter method for sqlite_dbdata and sqlite_dbptr.
*/
static int dbdataFilter(
  sqlite3_vtab_cursor *pCursor, 
  int idxNum, const char *idxStr,
  int argc, sqlite3_value **argv
){
  DbdataCursor *pCsr = (DbdataCursor*)pCursor;
  DbdataTable *pTab = (DbdataTable*)pCursor->pVtab;
  int rc = SQLITE_OK;
  const char *zSchema = "main";

  dbdataResetCursor(pCsr);
  assert( pCsr->iPgno==1 );
  if( idxNum & 0x01 ){
    zSchema = (const char*)sqlite3_value_text(argv[0]);
  }
  if( idxNum & 0x02 ){
    pCsr->iPgno = sqlite3_value_int(argv[(idxNum & 0x01)]);
    pCsr->bOnePage = 1;
  }else{
    pCsr->nPage = dbdataDbsize(pCsr, zSchema);
    rc = dbdataDbsize(pCsr, zSchema);
  }

  if( rc==SQLITE_OK ){
    if( pTab->pStmt ){
      pCsr->pStmt = pTab->pStmt;
      pTab->pStmt = 0;
    }else{
      rc = sqlite3_prepare_v2(pTab->db, 
          "SELECT data FROM sqlite_dbpage(?) WHERE pgno=?", -1,
          &pCsr->pStmt, 0
      );
    }
  }
  if( rc==SQLITE_OK ){
    rc = sqlite3_bind_text(pCsr->pStmt, 1, zSchema, -1, SQLITE_TRANSIENT);
  }else{
    pTab->base.zErrMsg = sqlite3_mprintf("%s", sqlite3_errmsg(pTab->db));
  }
  if( rc==SQLITE_OK ){
    rc = dbdataNext(pCursor);
  }
  return rc;
}

/* 
** Return a column for the sqlite_dbdata or sqlite_dbptr table.
*/
static int dbdataColumn(
  sqlite3_vtab_cursor *pCursor, 
  sqlite3_context *ctx, 
  int i
){
  DbdataCursor *pCsr = (DbdataCursor*)pCursor;
  DbdataTable *pTab = (DbdataTable*)pCursor->pVtab;
  if( pTab->bPtr ){
    switch( i ){
      case DBPTR_COLUMN_PGNO:
        sqlite3_result_int64(ctx, pCsr->iPgno);
        break;
      case DBPTR_COLUMN_CHILD: {
        int iOff = pCsr->iPgno==1 ? 100 : 0;
        if( pCsr->iCell<0 ){
          iOff += 8;
        }else{
          iOff += 12 + pCsr->iCell*2;
          if( iOff>pCsr->nPage ) return SQLITE_OK;
          iOff = get_uint16(&pCsr->aPage[iOff]);
        }
        if( iOff<=pCsr->nPage ){
          sqlite3_result_int64(ctx, get_uint32(&pCsr->aPage[iOff]));
        }
        break;
      }
    }
  }else{
    switch( i ){
      case DBDATA_COLUMN_PGNO:
        sqlite3_result_int64(ctx, pCsr->iPgno);
        break;
      case DBDATA_COLUMN_CELL:
        sqlite3_result_int(ctx, pCsr->iCell);
        break;
      case DBDATA_COLUMN_FIELD:
        sqlite3_result_int(ctx, pCsr->iField);
        break;
      case DBDATA_COLUMN_VALUE: {
        if( pCsr->iField<0 ){
          sqlite3_result_int64(ctx, pCsr->iIntkey);
        }else{
          sqlite3_int64 iType;
          dbdataGetVarint(pCsr->pHdrPtr, &iType);
          dbdataValue(
              ctx, iType, pCsr->pPtr, &pCsr->pRec[pCsr->nRec] - pCsr->pPtr
          );
        }
        break;
      }
    }
  }
  return SQLITE_OK;
}

/* 
** Return the rowid for an sqlite_dbdata or sqlite_dptr table.
*/
static int dbdataRowid(sqlite3_vtab_cursor *pCursor, sqlite_int64 *pRowid){
  DbdataCursor *pCsr = (DbdataCursor*)pCursor;
  *pRowid = pCsr->iRowid;
  return SQLITE_OK;
}


/*
** Invoke this routine to register the "sqlite_dbdata" virtual table module
*/
static int sqlite3DbdataRegister(sqlite3 *db){
  static sqlite3_module dbdata_module = {
    0,                            /* iVersion */
    0,                            /* xCreate */
    dbdataConnect,                /* xConnect */
    dbdataBestIndex,              /* xBestIndex */
    dbdataDisconnect,             /* xDisconnect */
    0,                            /* xDestroy */
    dbdataOpen,                   /* xOpen - open a cursor */
    dbdataClose,                  /* xClose - close a cursor */
    dbdataFilter,                 /* xFilter - configure scan constraints */
    dbdataNext,                   /* xNext - advance a cursor */
    dbdataEof,                    /* xEof - check for end of scan */
    dbdataColumn,                 /* xColumn - read data */
    dbdataRowid,                  /* xRowid - read data */
    0,                            /* xUpdate */
    0,                            /* xBegin */
    0,                            /* xSync */
    0,                            /* xCommit */
    0,                            /* xRollback */
    0,                            /* xFindMethod */
    0,                            /* xRename */
    0,                            /* xSavepoint */
    0,                            /* xRelease */
    0,                            /* xRollbackTo */
    0                             /* xShadowName */
  };

  int rc = sqlite3_create_module(db, "sqlite_dbdata", &dbdata_module, 0);
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_module(db, "sqlite_dbptr", &dbdata_module, (void*)1);
  }
  return rc;
}

#ifdef _WIN32
__declspec(dllexport)
#endif
int sqlite3_dbdata_init(
  sqlite3 *db, 
  char **pzErrMsg, 
  const sqlite3_api_routines *pApi
){
  SQLITE_EXTENSION_INIT2(pApi);
  return sqlite3DbdataRegister(db);
}

/*
** 2019-04-17
**
** The author disclaims copyright to this source code.  In place of
** a legal notice, here is a blessing:
**
**    May you do good and not evil.
**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
******************************************************************************
**
** This file contains an implementation of two eponymous virtual tables,
** "sqlite_dbdata" and "sqlite_dbptr". Both modules require that the
** "sqlite_dbpage" eponymous virtual table be available.
**
** SQLITE_DBDATA:
**   sqlite_dbdata is used to extract data directly from a database b-tree
**   page and its associated overflow pages, bypassing the b-tree layer.
**   The table schema is equivalent to:
**
**     CREATE TABLE sqlite_dbdata(
**       pgno INTEGER,
**       cell INTEGER,
**       field INTEGER,
**       value ANY,
**       schema TEXT HIDDEN
**     );
**
**   IMPORTANT: THE VIRTUAL TABLE SCHEMA ABOVE IS SUBJECT TO CHANGE. IN THE
**   FUTURE NEW NON-HIDDEN COLUMNS MAY BE ADDED BETWEEN "value" AND
**   "schema".
**
**   Each page of the database is inspected. If it cannot be interpreted as
**   a b-tree page, or if it is a b-tree page containing 0 entries, the
**   sqlite_dbdata table contains no rows for that page.  Otherwise, the
**   table contains one row for each field in the record associated with
**   each cell on the page. For intkey b-trees, the key value is stored in
**   field -1.
**
**   For example, for the database:
**
**     CREATE TABLE t1(a, b);     -- root page is page 2
**     INSERT INTO t1(rowid, a, b) VALUES(5, 'v', 'five');
**     INSERT INTO t1(rowid, a, b) VALUES(10, 'x', 'ten');
**
**   the sqlite_dbdata table contains, as well as from entries related to 
**   page 1, content equivalent to:
**
**     INSERT INTO sqlite_dbdata(pgno, cell, field, value) VALUES
**         (2, 0, -1, 5     ),
**         (2, 0,  0, 'v'   ),
**         (2, 0,  1, 'five'),
**         (2, 1, -1, 10    ),
**         (2, 1,  0, 'x'   ),
**         (2, 1,  1, 'ten' );
**
**   If database corruption is encountered, this module does not report an
**   error. Instead, it attempts to extract as much data as possible and
**   ignores the corruption.
**
** SQLITE_DBPTR:
**   The sqlite_dbptr table has the following schema:
**
**     CREATE TABLE sqlite_dbptr(
**       pgno INTEGER,
**       child INTEGER,
**       schema TEXT HIDDEN
**     );
**
**   It contains one entry for each b-tree pointer between a parent and
**   child page in the database.
*/

#if !defined(SQLITEINT_H) 
#include "sqlite3ext.h"

typedef unsigned char u8;
typedef unsigned int u32;

#endif
SQLITE_EXTENSION_INIT1
#include <string.h>
#include <assert.h>

#ifndef SQLITE_OMIT_VIRTUALTABLE

#define DBDATA_PADDING_BYTES 100 

typedef struct DbdataTable DbdataTable;
typedef struct DbdataCursor DbdataCursor;

/* Cursor object */
struct DbdataCursor {
  sqlite3_vtab_cursor base;       /* Base class.  Must be first */
  sqlite3_stmt *pStmt;            /* For fetching database pages */

  int iPgno;                      /* Current page number */
  u8 *aPage;                      /* Buffer containing page */
  int nPage;                      /* Size of aPage[] in bytes */
  int nCell;                      /* Number of cells on aPage[] */
  int iCell;                      /* Current cell number */
  int bOnePage;                   /* True to stop after one page */
  int szDb;
  sqlite3_int64 iRowid;

  /* Only for the sqlite_dbdata table */
  u8 *pRec;                       /* Buffer containing current record */
  sqlite3_int64 nRec;             /* Size of pRec[] in bytes */
  sqlite3_int64 nHdr;             /* Size of header in bytes */
  int iField;                     /* Current field number */
  u8 *pHdrPtr;
  u8 *pPtr;
  u32 enc;                        /* Text encoding */
  
  sqlite3_int64 iIntkey;          /* Integer key value */
};

/* Table object */
struct DbdataTable {
  sqlite3_vtab base;              /* Base class.  Must be first */
  sqlite3 *db;                    /* The database connection */
  sqlite3_stmt *pStmt;            /* For fetching database pages */
  int bPtr;                       /* True for sqlite3_dbptr table */
};

/* Column and schema definitions for sqlite_dbdata */
#define DBDATA_COLUMN_PGNO        0
#define DBDATA_COLUMN_CELL        1
#define DBDATA_COLUMN_FIELD       2
#define DBDATA_COLUMN_VALUE       3
#define DBDATA_COLUMN_SCHEMA      4
#define DBDATA_SCHEMA             \
      "CREATE TABLE x("           \
      "  pgno INTEGER,"           \
      "  cell INTEGER,"           \
      "  field INTEGER,"          \
      "  value ANY,"              \
      "  schema TEXT HIDDEN"      \
      ")"

/* Column and schema definitions for sqlite_dbptr */
#define DBPTR_COLUMN_PGNO         0
#define DBPTR_COLUMN_CHILD        1
#define DBPTR_COLUMN_SCHEMA       2
#define DBPTR_SCHEMA              \
      "CREATE TABLE x("           \
      "  pgno INTEGER,"           \
      "  child INTEGER,"          \
      "  schema TEXT HIDDEN"      \
      ")"

/*
** Connect to an sqlite_dbdata (pAux==0) or sqlite_dbptr (pAux!=0) virtual 
** table.
*/
static int dbdataConnect(
  sqlite3 *db,
  void *pAux,
  int argc, const char *const*argv,
  sqlite3_vtab **ppVtab,
  char **pzErr
){
  DbdataTable *pTab = 0;
  int rc = sqlite3_declare_vtab(db, pAux ? DBPTR_SCHEMA : DBDATA_SCHEMA);

  if( rc==SQLITE_OK ){
    pTab = (DbdataTable*)sqlite3_malloc64(sizeof(DbdataTable));
    if( pTab==0 ){
      rc = SQLITE_NOMEM;
    }else{
      memset(pTab, 0, sizeof(DbdataTable));
      pTab->db = db;
      pTab->bPtr = (pAux!=0);
    }
  }

  *ppVtab = (sqlite3_vtab*)pTab;
  return rc;
}

/*
** Disconnect from or destroy a sqlite_dbdata or sqlite_dbptr virtual table.
*/
static int dbdataDisconnect(sqlite3_vtab *pVtab){
  DbdataTable *pTab = (DbdataTable*)pVtab;
  if( pTab ){
    sqlite3_finalize(pTab->pStmt);
    sqlite3_free(pVtab);
  }
  return SQLITE_OK;
}

/*
** This function interprets two types of constraints:
**
**       schema=?
**       pgno=?
**
** If neither are present, idxNum is set to 0. If schema=? is present,
** the 0x01 bit in idxNum is set. If pgno=? is present, the 0x02 bit
** in idxNum is set.
**
** If both parameters are present, schema is in position 0 and pgno in
** position 1.
*/
static int dbdataBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdx){
  DbdataTable *pTab = (DbdataTable*)tab;
  int i;
  int iSchema = -1;
  int iPgno = -1;
  int colSchema = (pTab->bPtr ? DBPTR_COLUMN_SCHEMA : DBDATA_COLUMN_SCHEMA);

  for(i=0; i<pIdx->nConstraint; i++){
    struct sqlite3_index_constraint *p = &pIdx->aConstraint[i];
    if( p->op==SQLITE_INDEX_CONSTRAINT_EQ ){
      if( p->iColumn==colSchema ){
        if( p->usable==0 ) return SQLITE_CONSTRAINT;
        iSchema = i;
      }
      if( p->iColumn==DBDATA_COLUMN_PGNO && p->usable ){
        iPgno = i;
      }
    }
  }

  if( iSchema>=0 ){
    pIdx->aConstraintUsage[iSchema].argvIndex = 1;
    pIdx->aConstraintUsage[iSchema].omit = 1;
  }
  if( iPgno>=0 ){
    pIdx->aConstraintUsage[iPgno].argvIndex = 1 + (iSchema>=0);
    pIdx->aConstraintUsage[iPgno].omit = 1;
    pIdx->estimatedCost = 100;
    pIdx->estimatedRows =  50;

    if( pTab->bPtr==0 && pIdx->nOrderBy && pIdx->aOrderBy[0].desc==0 ){
      int iCol = pIdx->aOrderBy[0].iColumn;
      if( pIdx->nOrderBy==1 ){
        pIdx->orderByConsumed = (iCol==0 || iCol==1);
      }else if( pIdx->nOrderBy==2 && pIdx->aOrderBy[1].desc==0 && iCol==0 ){
        pIdx->orderByConsumed = (pIdx->aOrderBy[1].iColumn==1);
      }
    }

  }else{
    pIdx->estimatedCost = 100000000;
    pIdx->estimatedRows = 1000000000;
  }
  pIdx->idxNum = (iSchema>=0 ? 0x01 : 0x00) | (iPgno>=0 ? 0x02 : 0x00);
  return SQLITE_OK;
}

/*
** Open a new sqlite_dbdata or sqlite_dbptr cursor.
*/
static int dbdataOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
  DbdataCursor *pCsr;

  pCsr = (DbdataCursor*)sqlite3_malloc64(sizeof(DbdataCursor));
  if( pCsr==0 ){
    return SQLITE_NOMEM;
  }else{
    memset(pCsr, 0, sizeof(DbdataCursor));
    pCsr->base.pVtab = pVTab;
  }

  *ppCursor = (sqlite3_vtab_cursor *)pCsr;
  return SQLITE_OK;
}

/*
** Restore a cursor object to the state it was in when first allocated 
** by dbdataOpen().
*/
static void dbdataResetCursor(DbdataCursor *pCsr){
  DbdataTable *pTab = (DbdataTable*)(pCsr->base.pVtab);
  if( pTab->pStmt==0 ){
    pTab->pStmt = pCsr->pStmt;
  }else{
    sqlite3_finalize(pCsr->pStmt);
  }
  pCsr->pStmt = 0;
  pCsr->iPgno = 1;
  pCsr->iCell = 0;
  pCsr->iField = 0;
  pCsr->bOnePage = 0;
  sqlite3_free(pCsr->aPage);
  sqlite3_free(pCsr->pRec);
  pCsr->pRec = 0;
  pCsr->aPage = 0;
}

/*
** Close an sqlite_dbdata or sqlite_dbptr cursor.
*/
static int dbdataClose(sqlite3_vtab_cursor *pCursor){
  DbdataCursor *pCsr = (DbdataCursor*)pCursor;
  dbdataResetCursor(pCsr);
  sqlite3_free(pCsr);
  return SQLITE_OK;
}

/* 
** Utility methods to decode 16 and 32-bit big-endian unsigned integers. 
*/
static u32 get_uint16(unsigned char *a){
  return (a[0]<<8)|a[1];
}
static u32 get_uint32(unsigned char *a){
  return ((u32)a[0]<<24)
       | ((u32)a[1]<<16)
       | ((u32)a[2]<<8)
       | ((u32)a[3]);
}

/*
** Load page pgno from the database via the sqlite_dbpage virtual table.
** If successful, set (*ppPage) to point to a buffer containing the page
** data, (*pnPage) to the size of that buffer in bytes and return
** SQLITE_OK. In this case it is the responsibility of the caller to
** eventually free the buffer using sqlite3_free().
**
** Or, if an error occurs, set both (*ppPage) and (*pnPage) to 0 and
** return an SQLite error code.
*/
static int dbdataLoadPage(
  DbdataCursor *pCsr,             /* Cursor object */
  u32 pgno,                       /* Page number of page to load */
  u8 **ppPage,                    /* OUT: pointer to page buffer */
  int *pnPage                     /* OUT: Size of (*ppPage) in bytes */
){
  int rc2;
  int rc = SQLITE_OK;
  sqlite3_stmt *pStmt = pCsr->pStmt;

  *ppPage = 0;
  *pnPage = 0;
  if( pgno>0 ){
    sqlite3_bind_int64(pStmt, 2, pgno);
    if( SQLITE_ROW==sqlite3_step(pStmt) ){
      int nCopy = sqlite3_column_bytes(pStmt, 0);
      if( nCopy>0 ){
        u8 *pPage;
        pPage = (u8*)sqlite3_malloc64(nCopy + DBDATA_PADDING_BYTES);
        if( pPage==0 ){
          rc = SQLITE_NOMEM;
        }else{
          const u8 *pCopy = sqlite3_column_blob(pStmt, 0);
          memcpy(pPage, pCopy, nCopy);
          memset(&pPage[nCopy], 0, DBDATA_PADDING_BYTES);
        }
        *ppPage = pPage;
        *pnPage = nCopy;
      }
    }
    rc2 = sqlite3_reset(pStmt);
    if( rc==SQLITE_OK ) rc = rc2;
  }

  return rc;
}

/*
** Read a varint.  Put the value in *pVal and return the number of bytes.
*/
static int dbdataGetVarint(const u8 *z, sqlite3_int64 *pVal){
  sqlite3_uint64 u = 0;
  int i;
  for(i=0; i<8; i++){
    u = (u<<7) + (z[i]&0x7f);
    if( (z[i]&0x80)==0 ){ *pVal = (sqlite3_int64)u; return i+1; }
  }
  u = (u<<8) + (z[i]&0xff);
  *pVal = (sqlite3_int64)u;
  return 9;
}

/*
** Like dbdataGetVarint(), but set the output to 0 if it is less than 0
** or greater than 0xFFFFFFFF. This can be used for all varints in an
** SQLite database except for key values in intkey tables.
*/
static int dbdataGetVarintU32(const u8 *z, sqlite3_int64 *pVal){
  sqlite3_int64 val;
  int nRet = dbdataGetVarint(z, &val);
  if( val<0 || val>0xFFFFFFFF ) val = 0;
  *pVal = val;
  return nRet;
}

/*
** Return the number of bytes of space used by an SQLite value of type
** eType.
*/
static int dbdataValueBytes(int eType){
  switch( eType ){
    case 0: case 8: case 9:
    case 10: case 11:
      return 0;
    case 1:
      return 1;
    case 2:
      return 2;
    case 3:
      return 3;
    case 4:
      return 4;
    case 5:
      return 6;
    case 6:
    case 7:
      return 8;
    default:
      if( eType>0 ){
        return ((eType-12) / 2);
      }
      return 0;
  }
}

/*
** Load a value of type eType from buffer pData and use it to set the
** result of context object pCtx.
*/
static void dbdataValue(
  sqlite3_context *pCtx, 
  u32 enc,
  int eType, 
  u8 *pData,
  int nData
){
  if( eType>=0 && dbdataValueBytes(eType)<=nData ){
    switch( eType ){
      case 0: 
      case 10: 
      case 11: 
        sqlite3_result_null(pCtx);
        break;
      
      case 8: 
        sqlite3_result_int(pCtx, 0);
        break;
      case 9:
        sqlite3_result_int(pCtx, 1);
        break;
  
      case 1: case 2: case 3: case 4: case 5: case 6: case 7: {
        sqlite3_uint64 v = (signed char)pData[0];
        pData++;
        switch( eType ){
          case 7:
          case 6:  v = (v<<16) + (pData[0]<<8) + pData[1];  pData += 2;
          case 5:  v = (v<<16) + (pData[0]<<8) + pData[1];  pData += 2;
          case 4:  v = (v<<8) + pData[0];  pData++;
          case 3:  v = (v<<8) + pData[0];  pData++;
          case 2:  v = (v<<8) + pData[0];  pData++;
        }
  
        if( eType==7 ){
          double r;
          memcpy(&r, &v, sizeof(r));
          sqlite3_result_double(pCtx, r);
        }else{
          sqlite3_result_int64(pCtx, (sqlite3_int64)v);
        }
        break;
      }
  
      default: {
        int n = ((eType-12) / 2);
        if( eType % 2 ){
          switch( enc ){
#ifndef SQLITE_OMIT_UTF16
            case SQLITE_UTF16BE:
              sqlite3_result_text16be(pCtx, (void*)pData, n, SQLITE_TRANSIENT);
              break;
            case SQLITE_UTF16LE:
              sqlite3_result_text16le(pCtx, (void*)pData, n, SQLITE_TRANSIENT);
              break;
#endif
            default:
              sqlite3_result_text(pCtx, (char*)pData, n, SQLITE_TRANSIENT);
              break;
          }
        }else{
          sqlite3_result_blob(pCtx, pData, n, SQLITE_TRANSIENT);
        }
      }
    }
  }
}

/*
** Move an sqlite_dbdata or sqlite_dbptr cursor to the next entry.
*/
static int dbdataNext(sqlite3_vtab_cursor *pCursor){
  DbdataCursor *pCsr = (DbdataCursor*)pCursor;
  DbdataTable *pTab = (DbdataTable*)pCursor->pVtab;

  pCsr->iRowid++;
  while( 1 ){
    int rc;
    int iOff = (pCsr->iPgno==1 ? 100 : 0);
    int bNextPage = 0;

    if( pCsr->aPage==0 ){
      while( 1 ){
        if( pCsr->bOnePage==0 && pCsr->iPgno>pCsr->szDb ) return SQLITE_OK;
        rc = dbdataLoadPage(pCsr, pCsr->iPgno, &pCsr->aPage, &pCsr->nPage);
        if( rc!=SQLITE_OK ) return rc;
        if( pCsr->aPage ) break;
        if( pCsr->bOnePage ) return SQLITE_OK;
        pCsr->iPgno++;
      }
      pCsr->iCell = pTab->bPtr ? -2 : 0;
      pCsr->nCell = get_uint16(&pCsr->aPage[iOff+3]);
    }

    if( pTab->bPtr ){
      if( pCsr->aPage[iOff]!=0x02 && pCsr->aPage[iOff]!=0x05 ){
        pCsr->iCell = pCsr->nCell;
      }
      pCsr->iCell++;
      if( pCsr->iCell>=pCsr->nCell ){
        sqlite3_free(pCsr->aPage);
        pCsr->aPage = 0;
        if( pCsr->bOnePage ) return SQLITE_OK;
        pCsr->iPgno++;
      }else{
        return SQLITE_OK;
      }
    }else{
      /* If there is no record loaded, load it now. */
      if( pCsr->pRec==0 ){
        int bHasRowid = 0;
        int nPointer = 0;
        sqlite3_int64 nPayload = 0;
        sqlite3_int64 nHdr = 0;
        int iHdr;
        int U, X;
        int nLocal;
  
        switch( pCsr->aPage[iOff] ){
          case 0x02:
            nPointer = 4;
            break;
          case 0x0a:
            break;
          case 0x0d:
            bHasRowid = 1;
            break;
          default:
            /* This is not a b-tree page with records on it. Continue. */
            pCsr->iCell = pCsr->nCell;
            break;
        }

        if( pCsr->iCell>=pCsr->nCell ){
          bNextPage = 1;
        }else{
  
          iOff += 8 + nPointer + pCsr->iCell*2;
          if( iOff>pCsr->nPage ){
            bNextPage = 1;
          }else{
            iOff = get_uint16(&pCsr->aPage[iOff]);
          }
    
          /* For an interior node cell, skip past the child-page number */
          iOff += nPointer;
    
          /* Load the "byte of payload including overflow" field */
          if( bNextPage || iOff>pCsr->nPage ){
            bNextPage = 1;
          }else{
            iOff += dbdataGetVarintU32(&pCsr->aPage[iOff], &nPayload);
          }
    
          /* If this is a leaf intkey cell, load the rowid */
          if( bHasRowid && !bNextPage && iOff<pCsr->nPage ){
            iOff += dbdataGetVarint(&pCsr->aPage[iOff], &pCsr->iIntkey);
          }
    
          /* Figure out how much data to read from the local page */
          U = pCsr->nPage;
          if( bHasRowid ){
            X = U-35;
          }else{
            X = ((U-12)*64/255)-23;
          }
          if( nPayload<=X ){
            nLocal = nPayload;
          }else{
            int M, K;
            M = ((U-12)*32/255)-23;
            K = M+((nPayload-M)%(U-4));
            if( K<=X ){
              nLocal = K;
            }else{
              nLocal = M;
            }
          }

          if( bNextPage || nLocal+iOff>pCsr->nPage ){
            bNextPage = 1;
          }else{

            /* Allocate space for payload. And a bit more to catch small buffer
            ** overruns caused by attempting to read a varint or similar from 
            ** near the end of a corrupt record.  */
            pCsr->pRec = (u8*)sqlite3_malloc64(nPayload+DBDATA_PADDING_BYTES);
            if( pCsr->pRec==0 ) return SQLITE_NOMEM;
            memset(pCsr->pRec, 0, nPayload+DBDATA_PADDING_BYTES);
            pCsr->nRec = nPayload;

            /* Load the nLocal bytes of payload */
            memcpy(pCsr->pRec, &pCsr->aPage[iOff], nLocal);
            iOff += nLocal;

            /* Load content from overflow pages */
            if( nPayload>nLocal ){
              sqlite3_int64 nRem = nPayload - nLocal;
              u32 pgnoOvfl = get_uint32(&pCsr->aPage[iOff]);
              while( nRem>0 ){
                u8 *aOvfl = 0;
                int nOvfl = 0;
                int nCopy;
                rc = dbdataLoadPage(pCsr, pgnoOvfl, &aOvfl, &nOvfl);
                assert( rc!=SQLITE_OK || aOvfl==0 || nOvfl==pCsr->nPage );
                if( rc!=SQLITE_OK ) return rc;
                if( aOvfl==0 ) break;

                nCopy = U-4;
                if( nCopy>nRem ) nCopy = nRem;
                memcpy(&pCsr->pRec[nPayload-nRem], &aOvfl[4], nCopy);
                nRem -= nCopy;

                pgnoOvfl = get_uint32(aOvfl);
                sqlite3_free(aOvfl);
              }
            }
    
            iHdr = dbdataGetVarintU32(pCsr->pRec, &nHdr);
            if( nHdr>nPayload ) nHdr = 0;
            pCsr->nHdr = nHdr;
            pCsr->pHdrPtr = &pCsr->pRec[iHdr];
            pCsr->pPtr = &pCsr->pRec[pCsr->nHdr];
            pCsr->iField = (bHasRowid ? -1 : 0);
          }
        }
      }else{
        pCsr->iField++;
        if( pCsr->iField>0 ){
          sqlite3_int64 iType;
          if( pCsr->pHdrPtr>&pCsr->pRec[pCsr->nRec] ){
            bNextPage = 1;
          }else{
            pCsr->pHdrPtr += dbdataGetVarintU32(pCsr->pHdrPtr, &iType);
            pCsr->pPtr += dbdataValueBytes(iType);
          }
        }
      }

      if( bNextPage ){
        sqlite3_free(pCsr->aPage);
        sqlite3_free(pCsr->pRec);
        pCsr->aPage = 0;
        pCsr->pRec = 0;
        if( pCsr->bOnePage ) return SQLITE_OK;
        pCsr->iPgno++;
      }else{
        if( pCsr->iField<0 || pCsr->pHdrPtr<&pCsr->pRec[pCsr->nHdr] ){
          return SQLITE_OK;
        }

        /* Advance to the next cell. The next iteration of the loop will load
        ** the record and so on. */
        sqlite3_free(pCsr->pRec);
        pCsr->pRec = 0;
        pCsr->iCell++;
      }
    }
  }

  assert( !"can't get here" );
  return SQLITE_OK;
}

/* 
** Return true if the cursor is at EOF.
*/
static int dbdataEof(sqlite3_vtab_cursor *pCursor){
  DbdataCursor *pCsr = (DbdataCursor*)pCursor;
  return pCsr->aPage==0;
}

/*
** Return true if nul-terminated string zSchema ends in "()". Or false
** otherwise.
*/
static int dbdataIsFunction(const char *zSchema){
  size_t n = strlen(zSchema);
  if( n>2 && zSchema[n-2]=='(' && zSchema[n-1]==')' ){
    return (int)n-2;
  }
  return 0;
}

/* 
** Determine the size in pages of database zSchema (where zSchema is
** "main", "temp" or the name of an attached database) and set 
** pCsr->szDb accordingly. If successful, return SQLITE_OK. Otherwise,
** an SQLite error code.
*/
static int dbdataDbsize(DbdataCursor *pCsr, const char *zSchema){
  DbdataTable *pTab = (DbdataTable*)pCsr->base.pVtab;
  char *zSql = 0;
  int rc, rc2;
  int nFunc = 0;
  sqlite3_stmt *pStmt = 0;

  if( (nFunc = dbdataIsFunction(zSchema))>0 ){
    zSql = sqlite3_mprintf("SELECT %.*s(0)", nFunc, zSchema);
  }else{
    zSql = sqlite3_mprintf("PRAGMA %Q.page_count", zSchema);
  }
  if( zSql==0 ) return SQLITE_NOMEM;

  rc = sqlite3_prepare_v2(pTab->db, zSql, -1, &pStmt, 0);
  sqlite3_free(zSql);
  if( rc==SQLITE_OK && sqlite3_step(pStmt)==SQLITE_ROW ){
    pCsr->szDb = sqlite3_column_int(pStmt, 0);
  }
  rc2 = sqlite3_finalize(pStmt);
  if( rc==SQLITE_OK ) rc = rc2;
  return rc;
}

/*
** Attempt to figure out the encoding of the database by retrieving page 1
** and inspecting the header field. If successful, set the pCsr->enc variable
** and return SQLITE_OK. Otherwise, return an SQLite error code.
*/
static int dbdataGetEncoding(DbdataCursor *pCsr){
  int rc = SQLITE_OK;
  int nPg1 = 0;
  u8 *aPg1 = 0;
  rc = dbdataLoadPage(pCsr, 1, &aPg1, &nPg1);
  assert( rc!=SQLITE_OK || nPg1==0 || nPg1>=512 );
  if( rc==SQLITE_OK && nPg1>0 ){
    pCsr->enc = get_uint32(&aPg1[56]);
  }
  sqlite3_free(aPg1);
  return rc;
}


/* 
** xFilter method for sqlite_dbdata and sqlite_dbptr.
*/
static int dbdataFilter(
  sqlite3_vtab_cursor *pCursor, 
  int idxNum, const char *idxStr,
  int argc, sqlite3_value **argv
){
  DbdataCursor *pCsr = (DbdataCursor*)pCursor;
  DbdataTable *pTab = (DbdataTable*)pCursor->pVtab;
  int rc = SQLITE_OK;
  const char *zSchema = "main";

  dbdataResetCursor(pCsr);
  assert( pCsr->iPgno==1 );
  if( idxNum & 0x01 ){
    zSchema = (const char*)sqlite3_value_text(argv[0]);
    if( zSchema==0 ) zSchema = "";
  }
  if( idxNum & 0x02 ){
    pCsr->iPgno = sqlite3_value_int(argv[(idxNum & 0x01)]);
    pCsr->bOnePage = 1;
  }else{
    rc = dbdataDbsize(pCsr, zSchema);
  }

  if( rc==SQLITE_OK ){
    int nFunc = 0;
    if( pTab->pStmt ){
      pCsr->pStmt = pTab->pStmt;
      pTab->pStmt = 0;
    }else if( (nFunc = dbdataIsFunction(zSchema))>0 ){
      char *zSql = sqlite3_mprintf("SELECT %.*s(?2)", nFunc, zSchema);
      if( zSql==0 ){
        rc = SQLITE_NOMEM;
      }else{
        rc = sqlite3_prepare_v2(pTab->db, zSql, -1, &pCsr->pStmt, 0);
        sqlite3_free(zSql);
      }
    }else{
      rc = sqlite3_prepare_v2(pTab->db, 
          "SELECT data FROM sqlite_dbpage(?) WHERE pgno=?", -1,
          &pCsr->pStmt, 0
      );
    }
  }
  if( rc==SQLITE_OK ){
    rc = sqlite3_bind_text(pCsr->pStmt, 1, zSchema, -1, SQLITE_TRANSIENT);
  }else{
    pTab->base.zErrMsg = sqlite3_mprintf("%s", sqlite3_errmsg(pTab->db));
  }

  /* Try to determine the encoding of the db by inspecting the header
  ** field on page 1. */
  if( rc==SQLITE_OK ){
    rc = dbdataGetEncoding(pCsr);
  }

  if( rc==SQLITE_OK ){
    rc = dbdataNext(pCursor);
  }
  return rc;
}

/*
** Return a column for the sqlite_dbdata or sqlite_dbptr table.
*/
static int dbdataColumn(
  sqlite3_vtab_cursor *pCursor, 
  sqlite3_context *ctx, 
  int i
){
  DbdataCursor *pCsr = (DbdataCursor*)pCursor;
  DbdataTable *pTab = (DbdataTable*)pCursor->pVtab;
  if( pTab->bPtr ){
    switch( i ){
      case DBPTR_COLUMN_PGNO:
        sqlite3_result_int64(ctx, pCsr->iPgno);
        break;
      case DBPTR_COLUMN_CHILD: {
        int iOff = pCsr->iPgno==1 ? 100 : 0;
        if( pCsr->iCell<0 ){
          iOff += 8;
        }else{
          iOff += 12 + pCsr->iCell*2;
          if( iOff>pCsr->nPage ) return SQLITE_OK;
          iOff = get_uint16(&pCsr->aPage[iOff]);
        }
        if( iOff<=pCsr->nPage ){
          sqlite3_result_int64(ctx, get_uint32(&pCsr->aPage[iOff]));
        }
        break;
      }
    }
  }else{
    switch( i ){
      case DBDATA_COLUMN_PGNO:
        sqlite3_result_int64(ctx, pCsr->iPgno);
        break;
      case DBDATA_COLUMN_CELL:
        sqlite3_result_int(ctx, pCsr->iCell);
        break;
      case DBDATA_COLUMN_FIELD:
        sqlite3_result_int(ctx, pCsr->iField);
        break;
      case DBDATA_COLUMN_VALUE: {
        if( pCsr->iField<0 ){
          sqlite3_result_int64(ctx, pCsr->iIntkey);
        }else{
          sqlite3_int64 iType;
          dbdataGetVarintU32(pCsr->pHdrPtr, &iType);
          dbdataValue(
              ctx, pCsr->enc, iType, pCsr->pPtr, 
              &pCsr->pRec[pCsr->nRec] - pCsr->pPtr
          );
        }
        break;
      }
    }
  }
  return SQLITE_OK;
}

/* 
** Return the rowid for an sqlite_dbdata or sqlite_dptr table.
*/
static int dbdataRowid(sqlite3_vtab_cursor *pCursor, sqlite_int64 *pRowid){
  DbdataCursor *pCsr = (DbdataCursor*)pCursor;
  *pRowid = pCsr->iRowid;
  return SQLITE_OK;
}


/*
** Invoke this routine to register the "sqlite_dbdata" virtual table module
*/
static int sqlite3DbdataRegister(sqlite3 *db){
  static sqlite3_module dbdata_module = {
    0,                            /* iVersion */
    0,                            /* xCreate */
    dbdataConnect,                /* xConnect */
    dbdataBestIndex,              /* xBestIndex */
    dbdataDisconnect,             /* xDisconnect */
    0,                            /* xDestroy */
    dbdataOpen,                   /* xOpen - open a cursor */
    dbdataClose,                  /* xClose - close a cursor */
    dbdataFilter,                 /* xFilter - configure scan constraints */
    dbdataNext,                   /* xNext - advance a cursor */
    dbdataEof,                    /* xEof - check for end of scan */
    dbdataColumn,                 /* xColumn - read data */
    dbdataRowid,                  /* xRowid - read data */
    0,                            /* xUpdate */
    0,                            /* xBegin */
    0,                            /* xSync */
    0,                            /* xCommit */
    0,                            /* xRollback */
    0,                            /* xFindMethod */
    0,                            /* xRename */
    0,                            /* xSavepoint */
    0,                            /* xRelease */
    0,                            /* xRollbackTo */
    0                             /* xShadowName */
  };

  int rc = sqlite3_create_module(db, "sqlite_dbdata", &dbdata_module, 0);
  if( rc==SQLITE_OK ){
    rc = sqlite3_create_module(db, "sqlite_dbptr", &dbdata_module, (void*)1);
  }
  return rc;
}

#ifdef _WIN32
__declspec(dllexport)
#endif
int sqlite3_dbdata_init(
  sqlite3 *db, 
  char **pzErrMsg, 
  const sqlite3_api_routines *pApi
){
  SQLITE_EXTENSION_INIT2(pApi);
  return sqlite3DbdataRegister(db);
}

#endif /* ifndef SQLITE_OMIT_VIRTUALTABLE */

# 2022 August 28
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
#

source [file join [file dirname [info script]] recover_common.tcl]
set testprefix recover1

proc compare_result {db1 db2 sql} {
  set r1 [$db1 eval $sql]
  set r2 [$db2 eval $sql]
  if {$r1 != $r2} {
    puts "r1: $r1"
    puts "r2: $r2"
    error "mismatch for $sql"
  }
  return ""
}

proc compare_dbs {db1 db2} {
  compare_result $db1 $db2 "SELECT sql FROM sqlite_master ORDER BY 1"
  foreach tbl [$db1 eval {SELECT name FROM sqlite_master WHERE type='table'}] {
    compare_result $db1 $db2 "SELECT * FROM $tbl"
  }

  compare_result $db1 $db2 "PRAGMA page_size"
  compare_result $db1 $db2 "PRAGMA auto_vacuum"
  compare_result $db1 $db2 "PRAGMA encoding"
  compare_result $db1 $db2 "PRAGMA user_version"
  compare_result $db1 $db2 "PRAGMA application_id"
}

proc do_recover_test {tn} {
  forcedelete test.db2
  forcedelete rstate.db

  uplevel [list do_test $tn.1 {
    set R [sqlite3_recover_init db main test.db2]
    $R config testdb rstate.db
    $R run
    $R finish
  } {}]

  sqlite3 db2 test.db2
  uplevel [list do_test $tn.2 [list compare_dbs db db2] {}]
  db2 close

  forcedelete test.db2
  forcedelete rstate.db

  uplevel [list do_test $tn.3 {
    set ::sqlhook [list]
    set R [sqlite3_recover_init_sql db main my_sql_hook]
    $R config testdb rstate.db
    $R config rowids 1
    $R run
    $R finish
  } {}]

  sqlite3 db2 test.db2
  execsql [join $::sqlhook ";"] db2
  db2 close
  sqlite3 db2 test.db2
  uplevel [list do_test $tn.4 [list compare_dbs db db2] {}]
  db2 close
}

proc my_sql_hook {sql} {
  lappend ::sqlhook $sql
  return 0
}

do_execsql_test 1.0 {
  CREATE TABLE t1(a INTEGER PRIMARY KEY, b);
  CREATE TABLE t2(a INTEGER PRIMARY KEY, b) WITHOUT ROWID;
  WITH s(i) AS (
    SELECT 1 UNION ALL SELECT i+1 FROM s WHERE i<10
  )
  INSERT INTO t1 SELECT i*2, hex(randomblob(250)) FROM s;
  INSERT INTO t2 SELECT * FROM t1;
}

do_recover_test 1

do_execsql_test 2.0 {
  ALTER TABLE t1 ADD COLUMN c DEFAULT 'xyz'
}
do_recover_test 2

do_execsql_test 3.0 {
  CREATE INDEX i1 ON t1(c);
}
do_recover_test 3

do_execsql_test 4.0 {
  CREATE VIEW v1 AS SELECT * FROM t2;
}
do_recover_test 4

do_execsql_test 5.0 {
  CREATE UNIQUE INDEX i2 ON t1(c, b);
}
do_recover_test 5

#--------------------------------------------------------------------------
#
reset_db
do_execsql_test 6.0 {
  CREATE TABLE t1(
      a INTEGER PRIMARY KEY,
      b INT,
      c TEXT,
      d INT GENERATED ALWAYS AS (a*abs(b)) VIRTUAL,
      e TEXT GENERATED ALWAYS AS (substr(c,b,b+1)) STORED,
      f TEXT GENERATED ALWAYS AS (substr(c,b,b+1)) STORED
  );

  INSERT INTO t1 VALUES(1, 2, 'hello world');
}
do_recover_test 6

do_execsql_test 7.0 {
  CREATE TABLE t2(i, j GENERATED ALWAYS AS (i+1) STORED, k);
  INSERT INTO t2 VALUES(10, 'ten');
}
do_execsql_test 7.1 {
  SELECT * FROM t2
} {10 11 ten}

do_recover_test 7.2

#--------------------------------------------------------------------------
#
reset_db
do_execsql_test 8.0 {
  CREATE TABLE x1(a INTEGER PRIMARY KEY AUTOINCREMENT, b, c);
  WITH s(i) AS (
    SELECT 1 UNION ALL SELECT i+1 FROM s WHERE i<2
  )
  INSERT INTO x1(b, c) SELECT hex(randomblob(100)), hex(randomblob(100)) FROM s;
  
  CREATE INDEX x1b ON x1(b);
  CREATE INDEX x1cb ON x1(c, b);
  DELETE FROM x1 WHERE a>50;

  ANALYZE;
}

do_recover_test 8

#-------------------------------------------------------------------------
reset_db
ifcapable fts5 {
  do_execsql_test 9.1 {
    CREATE VIRTUAL TABLE ft5 USING fts5(a, b);
    INSERT INTO ft5 VALUES('hello', 'world');
  }
  do_recover_test 9 
}

#-------------------------------------------------------------------------
reset_db
do_execsql_test 10.1 {
  CREATE TABLE x1(a PRIMARY KEY, str TEXT) WITHOUT ROWID;
  INSERT INTO x1 VALUES(1, '
    \nhello\012world(\n0)(\n1)
  ');
  INSERT INTO x1 VALUES(2, '
    \nhello
  ');
}
do_execsql_test 10.2 "
  INSERT INTO x1 VALUES(3, '\012hello there\015world');
  INSERT INTO x1 VALUES(4, '\015hello there\015world');
"
do_recover_test 10 

#-------------------------------------------------------------------------
reset_db
do_execsql_test 11.1 {
  PRAGMA page_size = 4096;
  PRAGMA encoding='utf16';
  PRAGMA auto_vacuum = 2;
  PRAGMA user_version = 45;
  PRAGMA application_id = 22;

  CREATE TABLE u1(u, v);
  INSERT INTO u1 VALUES('edvin marton', 'bond');
  INSERT INTO u1 VALUES(1, 4.0);
}
do_execsql_test 11.1a {
  PRAGMA auto_vacuum;
} {2}

do_recover_test 11 

do_test 12.1 {
  set R [sqlite3_recover_init db "" test.db2]
  $R config lostandfound ""
  $R config invalid xyz
} {12}
do_test 12.2 {
  $R run
  $R run
} {0}

do_test 12.3 {
  $R finish
} {}



#-------------------------------------------------------------------------
reset_db
file_control_reservebytes db 16
do_execsql_test 12.1 {
  PRAGMA auto_vacuum = 2;
  PRAGMA user_version = 45;
  PRAGMA application_id = 22;

  CREATE TABLE u1(u, v);
  CREATE UNIQUE INDEX i1 ON u1(u, v);
  INSERT INTO u1 VALUES(1, 2), (3, 4);

  CREATE TABLE u2(u, v);
  CREATE UNIQUE INDEX i2 ON u1(u, v);
  INSERT INTO u2 VALUES(hex(randomblob(500)), hex(randomblob(1000)));
  INSERT INTO u2 VALUES(hex(randomblob(500)), hex(randomblob(1000)));
  INSERT INTO u2 VALUES(hex(randomblob(500)), hex(randomblob(1000)));
  INSERT INTO u2 VALUES(hex(randomblob(50000)), hex(randomblob(20000)));
}

do_recover_test 12 

#-------------------------------------------------------------------------
reset_db
sqlite3 db "" 
do_recover_test 13

do_execsql_test 14.1 {
  PRAGMA auto_vacuum = 2;
  PRAGMA user_version = 45;
  PRAGMA application_id = 22;

  CREATE TABLE u1(u, v);
  CREATE UNIQUE INDEX i1 ON u1(u, v);
  INSERT INTO u1 VALUES(1, 2), (3, 4);

  CREATE TABLE u2(u, v);
  CREATE UNIQUE INDEX i2 ON u1(u, v);
  INSERT INTO u2 VALUES(hex(randomblob(500)), hex(randomblob(1000)));
  INSERT INTO u2 VALUES(hex(randomblob(500)), hex(randomblob(1000)));
  INSERT INTO u2 VALUES(hex(randomblob(500)), hex(randomblob(1000)));
  INSERT INTO u2 VALUES(hex(randomblob(50000)), hex(randomblob(20000)));
}
do_recover_test 14 

#-------------------------------------------------------------------------
reset_db
do_execsql_test 15.1 {
  PRAGMA journal_mode=OFF;
  PRAGMA mmap_size=10;
  CREATE TABLE t1(x);
} {off 10}
do_recover_test 15 

finish_test

if {![info exists testdir]} {
  set testdir [file join [file dirname [info script]] .. .. test]
} 
source $testdir/tester.tcl

if {[info commands sqlite3_recover_init]==""} {
  finish_test
  return -code return
}

# 2019 April 23
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
# 
# Tests for the SQLITE_RECOVER_ROWIDS option.
#

source [file join [file dirname [info script]] recover_common.tcl]
set testprefix recoverclobber

proc recover {db output} {
  set R [sqlite3_recover_init db main test.db2]
  $R run
  $R finish
}

forcedelete test.db2
do_execsql_test 1.0 {
  ATTACH 'test.db2' AS aux;
  CREATE TABLE aux.x1(x, one);
  INSERT INTO x1 VALUES(1, 'one'), (2, 'two'), (3, 'three');

  CREATE TABLE t1(a, b);
  INSERT INTO t1 VALUES(1, 1), (2, 2), (3, 3), (4, 4);

  DETACH aux;
}

breakpoint
do_test 1.1 {
  recover db test.db2
} {}

do_execsql_test 1.2 {
  ATTACH 'test.db2' AS aux;
  SELECT * FROM aux.t1;
} {1 1   2 2   3 3   4 4}

do_catchsql_test 1.3 {
  SELECT * FROM aux.x1;
} {1 {no such table: aux.x1}}

finish_test

# 2022 August 28
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
#

source [file join [file dirname [info script]] recover_common.tcl]
set testprefix recovercorrupt

database_may_be_corrupt

do_execsql_test 1.0 {
  PRAGMA page_size = 512;
  CREATE TABLE t1(a INTEGER PRIMARY KEY, b, c);
  INSERT INTO t1 VALUES(1, 2, 3);
  INSERT INTO t1 VALUES(2, hex(randomblob(100)), randomblob(200));
  CREATE INDEX i1 ON t1(b, c);
  CREATE TABLE t2(a PRIMARY KEY, b, c) WITHOUT ROWID;
  INSERT INTO t2 VALUES(1, 2, 3);
  INSERT INTO t2 VALUES(2, hex(randomblob(100)), randomblob(200));
  ANALYZE;
  PRAGMA writable_schema = 1;
  DELETE FROM sqlite_schema WHERE name='t2';
}

do_test 1.1 {
  expr [file size test.db]>3072
} {1}

proc toggle_bit {blob bit} {
  set byte [expr {$bit / 8}]
  set bit [expr {$bit & 0x0F}]
  binary scan $blob a${byte}ca* A x B
  set x [expr {$x ^ (1 << $bit)}]
  binary format a*ca* $A $x $B
}


db_save_and_close
for {set ii 0} {$ii < 10000} {incr ii} {
  db_restore_and_reopen
  db func toggle_bit toggle_bit
  set bitsperpage [expr 512*8]

  set pg [expr {($ii / $bitsperpage)+1}]
  set byte [expr {$ii % $bitsperpage}]
  db eval {
    UPDATE sqlite_dbpage SET data = toggle_bit(data, $byte) WHERE pgno=$pg
  }

    set R [sqlite3_recover_init db main test.db2]
    $R config lostandfound lost_and_found
    $R run
  do_test 1.2.$ii {
    $R finish
  } {}
}


finish_test