/*
** 2020-05-12
**
******************************************************************************
**
** This file contains declarations for the public interface to code in
** bcvutil.c. This API allows applications to upload, download, duplicate and
** delete CBS cloud storage databases. It is also possible to create
** or destroy CBS manifests and cloud storage containers/buckets.
**
** In general API users proceed as follows:
**
** 1. A (sqlite3_bcv*) handle is created using sqlite3_bcv_open().
**
** 2. The handle is configured in various ways using zero or more
** calls to sqlite3_bcv_config().
**
** 3. Operations are performed on cloud storage using one or more
** calls to the following APIs:
**
** sqlite3_bcv_create() // create a new container/bucket
** sqlite3_bcv_destroy() // delete an entire container/bucket
** sqlite3_bcv_upload() // upload a database to cloud storage
** sqlite3_bcv_download() // download a database from cloud storage
** sqlite3_bcv_copy() // duplicate a database within cloud storage
** sqlite3_bcv_delete() // delete a single database from cloud storage
** sqlite3_bcv_cleanup() // delete unused blocks from cloud storage
**
** 4. The (sqlite3_bcv*) handle is deleted, freeing all allocated resources,
** by calling sqlite3_bcv_close().
**
** The calls made in steps 2 and 3 above may be interwoven - a handle may
** be configured or reconfigured at any time, not only immediately after it
** is created.
**
** If an error occurs, the sqlite3_bcv_errmsg() API may in some cases be used
** to obtain an English language error message.
**
** Calls that return an integer error code may return either a non-extended
** SQLite error code (rc < 400) or an HTTP error code (rc >= 400) if an
** HTTP error occurs.
*/
#ifndef _BCVUTIL_H
#define _BCVUTIL_H 1
#ifdef __cplusplus
extern "C" {
#endif
typedef struct sqlite3_bcv sqlite3_bcv;
/*
** Allocate a new sqlite3_bcv handle.
**
** The first argument is passed the name of the module to use. This may
** be either a simple module name (e.g. "google") or a module name with
** URI style parameters (e.g. "azure?emulator=127.0.0.1:10000&sas=1").
**
** The second parameter is passed the user or account name that will be
** used to access the cloud storage container. The third parameter, zAuth,
** must be passed a nul-terminated string containing the authentication
** information to use when accessing the remote resource. Refer to
** documentation for the specific cloud storage module in use for exactly
** how this value, and the user name value, are used.
**
** The fourth parameter, zContainer, is passed the name of the remote
** container to operate on.
**
** If successful, SQLITE_OK is returned and output variable (*ppOut) set
** to contain a pointer to the new handle. Or, if an error occurs, an
** SQLite error code is returned. In this case (*ppOut) is still set to
** point to a new handle, but passing it to any function except
** sqlite3_bcv_close() and sqlite3_bcv_errmsg() is a no-op that returns
** a copy of the error code returned by sqlite3_bcv_open(). An application
** may use sqlite3_bcv_errmsg() to obtain an English language error message
** before closing the handle in this case.
*/
int sqlite3_bcv_open(
const char *zModule,
const char *zUser, /* Cloud storage user name */
const char *zAuth, /* Key or SAS used for cloud storage auth. */
const char *zContainer, /* Cloud storage container/bucket */
sqlite3_bcv **ppOut /* OUT: New object */
);
/*
** Configure the bcv handle passed as the first argument.
*/
int sqlite3_bcv_config(sqlite3_bcv*, int eOp, ...);
/*
** SQLITE_BCVCONFIG_VERBOSE:
** A single trailing int is required by this configuration option. If
** non-zero, the handle is configured to use CURLOPT_VERBOSE with all
** http/https requests. If zero, it is configured to not use
** CURLOPT_VERBOSE. The default is not to use CURLOPT_VERBOSE.
**
** SQLITE_BCVCONFIG_PROGRESS:
** Configure a callback to be issued after each block is
** uploaded/downloaded within sqlite3_bcv_upload()/download() API calls.
** This configuration option requires two trailing arguments, a (void*)
** and a function with the following signature:
**
** int xProgress(void *pCtx, sqlite3_int64 nDone, sqlite3_int64 nTotal);
**
** Within a call to sqlite3_bcv_upload(), the callback is invoked after
** each block has been uploaded. The three arguments are a copy of the
** (void*) passed to sqlite3_bcv_config(), the number of bytes uploaded
** by the current call so far, and the total number of bytes that will
** be uploaded, assuming the call is successful, before returning.
** For a sqlite3_bcv_download() call, the callback is invoked after each
** block has been downloaded. The three arguments are similar to those
** for _upload() - a copy of the (void*), the number of bytes downloaded
** so far, and the total bytes that will be downloaded.
**
** If the progress callback returns 0, the operation continues. If it
** returns a non-zero value, the operation is abandoned and error code
** SQLITE_ABORT returned to the caller.
**
** SQLITE_BCVCONFIG_LOG:
** Configure a callback to be invoked each time an HTTP(S) request is
** sent, and each time a reply is received. The trailing arguments for
** this option are a (void*) and a function with the following signature:
**
** void xLog(void *pCtx, const char*);
**
** Each time the callback is invoked, a copy of the first trailing
** argument passed to the sqlite3_bcv_config() call is passed as its
** first parameter. The second parameter points to a nul-terminated
** string containing a human-readable message suitable for outputing
** to a log file.
**
** SQLITE_BCVCONFIG_LOGLEVEL:
** Set the verbosity level of the debugging messages output to
** the SQLITE_BCVCONFIG_LOG callback. The default (and recommended)
** level is 0. Higher values produce more logging output.
**
** SQLITE_BCVCONFIG_NREQUEST:
** This option requires a single trailing argument of type int. It
** sets the maximum number of simultaneous HTTPS requests for an
** upload or download operation. Values are clipped to between 1
** and 32. The default value is 1.
**
** SQLITE_BCVCONFIG_TESTNOKV:
** Internal option used for testing only.
**
** SQLITE_BCVCONFIG_HTTPTIMEOUT:
** Sets the number of seconds before an HTTPS request is deemed
** to have timed out. Default is 600.
*/
#define SQLITE_BCVCONFIG_VERBOSE 1 /* (int) */
#define SQLITE_BCVCONFIG_PROGRESS 2 /* (void*,xProgress) */
#define SQLITE_BCVCONFIG_LOG 3 /* (void*,xLog) */
#define SQLITE_BCVCONFIG_NREQUEST 4 /* (int) */
#define SQLITE_BCVCONFIG_LOGLEVEL 5 /* (int) */
#define SQLITE_BCVCONFIG_TESTNOKV 6 /* (int) */
#define SQLITE_BCVCONFIG_HTTPTIMEOUT 7 /* (int) */
/*
** Delete an sqlite3_bcv handle obtained via an earlier call to
** sqlite3_bcv_open().
*/
void sqlite3_bcv_close(sqlite3_bcv*);
/*
** Return a copy of the error code returned by the most recent call to
** sqlite_bcv_create(), destroy(), upload(), download(), copy(), delete()
** or open() on the handle passed as the only argument.
*/
int sqlite3_bcv_errcode(sqlite3_bcv*);
/*
** If the most recent call to sqlite3_bcv_create(), destroy(), upload(),
** download(), copy(), delete() or open() encountered an error, return an
** English language error message describing the error that occurred. Or, if
** the most recent API call did not return an error, return NULL.
*/
const char *sqlite3_bcv_errmsg(sqlite3_bcv *p);
/*
** Upload a database to the cloud storage container. Argument zLocal
** identifies the database to upload from the local file-system. Argument
** zRemote is the name the database will take within cloud storage.
**
** If the operation is successful, SQLITE_OK is returned. Or, if
** an HTTPS request made to the cloud storage system fails, an HTTP
** response code is returned. Or, if some other error occurs (for example,
** a failed memory allocation), a non-extended SQLite error code is
** returned. All HTTP response codes that may be returned are greater
** than or equal to 400. All non-extended SQLite error codes are positive
** integers smaller than 256.
*/
int sqlite3_bcv_upload(
sqlite3_bcv *p,
const char *zLocal,
const char *zRemote
);
/*
** Download a database from the cloud storage container. Parameter zRemote
** is the name of the database within cloud storage, and zLocal is the
** local path at which the downloaded databse will be written.
**
** If the operation is successful, SQLITE_OK is returned. Or, if
** an HTTPS request made to the cloud storage system fails, an HTTP
** response code is returned. Or, if some other error occurs (for example,
** a failed memory allocation), a non-extended SQLite error code is
** returned. All HTTP response codes that may be returned are greater
** than or equal to 400. All non-extended SQLite error codes are positive
** integers smaller than 256.
*/
int sqlite3_bcv_download(
sqlite3_bcv *p,
const char *zRemote,
const char *zLocal
);
/*
** Create a copy of an existing cloud storage database within its container.
**
** If the operation is successful, SQLITE_OK is returned. Or, if
** an HTTPS request made to the cloud storage system fails, an HTTP
** response code is returned. Or, if some other error occurs (for example,
** a failed memory allocation), a non-extended SQLite error code is
** returned. All HTTP response codes that may be returned are greater
** than or equal to 400. All non-extended SQLite error codes are positive
** integers smaller than 256.
*/
int sqlite3_bcv_copy(
sqlite3_bcv *p,
const char *zFrom,
const char *zTo
);
/*
** Delete a database from cloud storage.
**
** If the operation is successful, SQLITE_OK is returned. Or, if
** an HTTPS request made to the cloud storage system fails, an HTTP
** response code is returned. Or, if some other error occurs (for example,
** a failed memory allocation), a non-extended SQLite error code is
** returned. All HTTP response codes that may be returned are greater
** than or equal to 400. All non-extended SQLite error codes are positive
** integers smaller than 256.
*/
int sqlite3_bcv_delete(
sqlite3_bcv *p,
const char *zDelete
);
/*
** Create a new cloud storage container and manifest file. If the container
** already exists, it is not an error, but any existing manifest file is
** simply clobbered.
**
** If the operation is successful, SQLITE_OK is returned. Or, if
** an HTTPS request made to the cloud storage system fails, an HTTP
** response code is returned. Or, if some other error occurs (for example,
** a failed memory allocation), a non-extended SQLite error code is
** returned. All HTTP response codes that may be returned are greater
** than or equal to 400. All non-extended SQLite error codes are positive
** integers smaller than 256.
*/
int sqlite3_bcv_create(sqlite3_bcv *p, int szName, int szBlock);
/*
** Delete the entire cloud storage container or bucket.
**
** If the operation is successful, SQLITE_OK is returned. Or, if
** an HTTPS request made to the cloud storage system fails, an HTTP
** response code is returned. Or, if some other error occurs (for example,
** a failed memory allocation), a non-extended SQLite error code is
** returned. All HTTP response codes that may be returned are greater
** than or equal to 400. All non-extended SQLite error codes are positive
** integers smaller than 256.
*/
int sqlite3_bcv_destroy(sqlite3_bcv *p);
/*
** When a remote database is written, a subset of its blocks are replaced
** by new versions, sometimes leaving the originals unused by any database.
** In this case, they are not deleted immediately. Instead, they are
** marked as unused, ready for deletion at some later time. Calling this
** routine deletes all blocks in the named remote container that were
** marked as unused nSecond seconds or more ago. Calling this routine with
** the nSecond parameter set to 0 or less deletes all unused blocks.
**
** If the cloud storage container is being written simultaneously by some
** other client anywhere on the network, this function may return HTTPS
** error 412 (pre-condition failed).
**
** If the operation is successful, SQLITE_OK is returned. Or, if
** an HTTPS request made to the cloud storage system fails, an HTTP
** response code is returned. Or, if some other error occurs (for example,
** a failed memory allocation), a non-extended SQLite error code is
** returned. All HTTP response codes that may be returned are greater
** than or equal to 400. All non-extended SQLite error codes are positive
** integers smaller than 256.
*/
int sqlite3_bcv_cleanup(sqlite3_bcv *p, int nSecond);
#ifdef __cplusplus
} /* end of the extern "C" block */
#endif
#endif /* ifndef _BCVUTIL_H */