000001 /*
000002 ** 2010 October 28
000003 **
000004 ** The author disclaims copyright to this source code. In place of
000005 ** a legal notice, here is a blessing:
000006 **
000007 ** May you do good and not evil.
000008 ** May you find forgiveness for yourself and forgive others.
000009 ** May you share freely, never taking more than you give.
000010 **
000011 *************************************************************************
000012 **
000013 ** This file contains a VFS "shim" - a layer that sits in between the
000014 ** pager and the real VFS - that breaks up a very large database file
000015 ** into two or more smaller files on disk. This is useful, for example,
000016 ** in order to support large, multi-gigabyte databases on older filesystems
000017 ** that limit the maximum file size to 2 GiB.
000018 **
000019 ** USAGE:
000020 **
000021 ** Compile this source file and link it with your application. Then
000022 ** at start-time, invoke the following procedure:
000023 **
000024 ** int sqlite3_multiplex_initialize(
000025 ** const char *zOrigVfsName, // The underlying real VFS
000026 ** int makeDefault // True to make multiplex the default VFS
000027 ** );
000028 **
000029 ** The procedure call above will create and register a new VFS shim named
000030 ** "multiplex". The multiplex VFS will use the VFS named by zOrigVfsName to
000031 ** do the actual disk I/O. (The zOrigVfsName parameter may be NULL, in
000032 ** which case the default VFS at the moment sqlite3_multiplex_initialize()
000033 ** is called will be used as the underlying real VFS.)
000034 **
000035 ** If the makeDefault parameter is TRUE then multiplex becomes the new
000036 ** default VFS. Otherwise, you can use the multiplex VFS by specifying
000037 ** "multiplex" as the 4th parameter to sqlite3_open_v2() or by employing
000038 ** URI filenames and adding "vfs=multiplex" as a parameter to the filename
000039 ** URI.
000040 **
000041 ** The multiplex VFS allows databases up to 32 GiB in size. But it splits
000042 ** the files up into smaller pieces, so that they will work even on
000043 ** filesystems that do not support large files. The default chunk size
000044 ** is 2147418112 bytes (which is 64KiB less than 2GiB) but this can be
000045 ** changed at compile-time by defining the SQLITE_MULTIPLEX_CHUNK_SIZE
000046 ** macro. Use the "chunksize=NNNN" query parameter with a URI filename
000047 ** in order to select an alternative chunk size for individual connections
000048 ** at run-time.
000049 */
000050 #include "sqlite3.h"
000051 #include <string.h>
000052 #include <assert.h>
000053 #include <stdlib.h>
000054 #include "test_multiplex.h"
000055
000056 #ifndef SQLITE_CORE
000057 #define SQLITE_CORE 1 /* Disable the API redefinition in sqlite3ext.h */
000058 #endif
000059 #include "sqlite3ext.h"
000060
000061 /*
000062 ** These should be defined to be the same as the values in
000063 ** sqliteInt.h. They are defined separately here so that
000064 ** the multiplex VFS shim can be built as a loadable
000065 ** module.
000066 */
000067 #define UNUSED_PARAMETER(x) (void)(x)
000068 #define MAX_PAGE_SIZE 0x10000
000069 #define DEFAULT_SECTOR_SIZE 0x1000
000070
000071 /* Maximum chunk number */
000072 #define MX_CHUNK_NUMBER 299
000073
000074 /* First chunk for rollback journal files */
000075 #define SQLITE_MULTIPLEX_JOURNAL_8_3_OFFSET 400
000076 #define SQLITE_MULTIPLEX_WAL_8_3_OFFSET 700
000077
000078
000079 /************************ Shim Definitions ******************************/
000080
000081 #ifndef SQLITE_MULTIPLEX_VFS_NAME
000082 # define SQLITE_MULTIPLEX_VFS_NAME "multiplex"
000083 #endif
000084
000085 /* This is the limit on the chunk size. It may be changed by calling
000086 ** the xFileControl() interface. It will be rounded up to a
000087 ** multiple of MAX_PAGE_SIZE. We default it here to 2GiB less 64KiB.
000088 */
000089 #ifndef SQLITE_MULTIPLEX_CHUNK_SIZE
000090 # define SQLITE_MULTIPLEX_CHUNK_SIZE 2147418112
000091 #endif
000092
000093 /* This used to be the default limit on number of chunks, but
000094 ** it is no longer enforced. There is currently no limit to the
000095 ** number of chunks.
000096 **
000097 ** May be changed by calling the xFileControl() interface.
000098 */
000099 #ifndef SQLITE_MULTIPLEX_MAX_CHUNKS
000100 # define SQLITE_MULTIPLEX_MAX_CHUNKS 12
000101 #endif
000102
000103 /************************ Object Definitions ******************************/
000104
000105 /* Forward declaration of all object types */
000106 typedef struct multiplexGroup multiplexGroup;
000107 typedef struct multiplexConn multiplexConn;
000108
000109 /*
000110 ** A "multiplex group" is a collection of files that collectively
000111 ** makeup a single SQLite DB file. This allows the size of the DB
000112 ** to exceed the limits imposed by the file system.
000113 **
000114 ** There is an instance of the following object for each defined multiplex
000115 ** group.
000116 */
000117 struct multiplexGroup {
000118 struct multiplexReal { /* For each chunk */
000119 sqlite3_file *p; /* Handle for the chunk */
000120 char *z; /* Name of this chunk */
000121 } *aReal; /* list of all chunks */
000122 int nReal; /* Number of chunks */
000123 char *zName; /* Base filename of this group */
000124 int nName; /* Length of base filename */
000125 int flags; /* Flags used for original opening */
000126 unsigned int szChunk; /* Chunk size used for this group */
000127 unsigned char bEnabled; /* TRUE to use Multiplex VFS for this file */
000128 unsigned char bTruncate; /* TRUE to enable truncation of databases */
000129 };
000130
000131 /*
000132 ** An instance of the following object represents each open connection
000133 ** to a file that is multiplex'ed. This object is a
000134 ** subclass of sqlite3_file. The sqlite3_file object for the underlying
000135 ** VFS is appended to this structure.
000136 */
000137 struct multiplexConn {
000138 sqlite3_file base; /* Base class - must be first */
000139 multiplexGroup *pGroup; /* The underlying group of files */
000140 };
000141
000142 /************************* Global Variables **********************************/
000143 /*
000144 ** All global variables used by this file are containing within the following
000145 ** gMultiplex structure.
000146 */
000147 static struct {
000148 /* The pOrigVfs is the real, original underlying VFS implementation.
000149 ** Most operations pass-through to the real VFS. This value is read-only
000150 ** during operation. It is only modified at start-time and thus does not
000151 ** require a mutex.
000152 */
000153 sqlite3_vfs *pOrigVfs;
000154
000155 /* The sThisVfs is the VFS structure used by this shim. It is initialized
000156 ** at start-time and thus does not require a mutex
000157 */
000158 sqlite3_vfs sThisVfs;
000159
000160 /* The sIoMethods defines the methods used by sqlite3_file objects
000161 ** associated with this shim. It is initialized at start-time and does
000162 ** not require a mutex.
000163 **
000164 ** When the underlying VFS is called to open a file, it might return
000165 ** either a version 1 or a version 2 sqlite3_file object. This shim
000166 ** has to create a wrapper sqlite3_file of the same version. Hence
000167 ** there are two I/O method structures, one for version 1 and the other
000168 ** for version 2.
000169 */
000170 sqlite3_io_methods sIoMethodsV1;
000171 sqlite3_io_methods sIoMethodsV2;
000172
000173 /* True when this shim has been initialized.
000174 */
000175 int isInitialized;
000176 } gMultiplex;
000177
000178 /************************* Utility Routines *********************************/
000179 /*
000180 ** Compute a string length that is limited to what can be stored in
000181 ** lower 30 bits of a 32-bit signed integer.
000182 **
000183 ** The value returned will never be negative. Nor will it ever be greater
000184 ** than the actual length of the string. For very long strings (greater
000185 ** than 1GiB) the value returned might be less than the true string length.
000186 */
000187 static int multiplexStrlen30(const char *z){
000188 const char *z2 = z;
000189 if( z==0 ) return 0;
000190 while( *z2 ){ z2++; }
000191 return 0x3fffffff & (int)(z2 - z);
000192 }
000193
000194 /*
000195 ** Generate the file-name for chunk iChunk of the group with base name
000196 ** zBase. The file-name is written to buffer zOut before returning. Buffer
000197 ** zOut must be allocated by the caller so that it is at least (nBase+5)
000198 ** bytes in size, where nBase is the length of zBase, not including the
000199 ** nul-terminator.
000200 **
000201 ** If iChunk is 0 (or 400 - the number for the first journal file chunk),
000202 ** the output is a copy of the input string. Otherwise, if
000203 ** SQLITE_ENABLE_8_3_NAMES is not defined or the input buffer does not contain
000204 ** a "." character, then the output is a copy of the input string with the
000205 ** three-digit zero-padded decimal representation if iChunk appended to it.
000206 ** For example:
000207 **
000208 ** zBase="test.db", iChunk=4 -> zOut="test.db004"
000209 **
000210 ** Or, if SQLITE_ENABLE_8_3_NAMES is defined and the input buffer contains
000211 ** a "." character, then everything after the "." is replaced by the
000212 ** three-digit representation of iChunk.
000213 **
000214 ** zBase="test.db", iChunk=4 -> zOut="test.004"
000215 **
000216 ** The output buffer string is terminated by 2 0x00 bytes. This makes it safe
000217 ** to pass to sqlite3_uri_parameter() and similar.
000218 */
000219 static void multiplexFilename(
000220 const char *zBase, /* Filename for chunk 0 */
000221 int nBase, /* Size of zBase in bytes (without \0) */
000222 int flags, /* Flags used to open file */
000223 int iChunk, /* Chunk to generate filename for */
000224 char *zOut /* Buffer to write generated name to */
000225 ){
000226 int n = nBase;
000227 memcpy(zOut, zBase, n+1);
000228 if( iChunk!=0 && iChunk<=MX_CHUNK_NUMBER ){
000229 #ifdef SQLITE_ENABLE_8_3_NAMES
000230 int i;
000231 for(i=n-1; i>0 && i>=n-4 && zOut[i]!='.'; i--){}
000232 if( i>=n-4 ) n = i+1;
000233 if( flags & SQLITE_OPEN_MAIN_JOURNAL ){
000234 /* The extensions on overflow files for main databases are 001, 002,
000235 ** 003 and so forth. To avoid name collisions, add 400 to the
000236 ** extensions of journal files so that they are 401, 402, 403, ....
000237 */
000238 iChunk += SQLITE_MULTIPLEX_JOURNAL_8_3_OFFSET;
000239 }else if( flags & SQLITE_OPEN_WAL ){
000240 /* To avoid name collisions, add 700 to the
000241 ** extensions of WAL files so that they are 701, 702, 703, ....
000242 */
000243 iChunk += SQLITE_MULTIPLEX_WAL_8_3_OFFSET;
000244 }
000245 #endif
000246 sqlite3_snprintf(4,&zOut[n],"%03d",iChunk);
000247 n += 3;
000248 }
000249
000250 assert( zOut[n]=='\0' );
000251 zOut[n+1] = '\0';
000252 }
000253
000254 /* Compute the filename for the iChunk-th chunk
000255 */
000256 static int multiplexSubFilename(multiplexGroup *pGroup, int iChunk){
000257 if( iChunk>=pGroup->nReal ){
000258 struct multiplexReal *p;
000259 p = sqlite3_realloc64(pGroup->aReal, (iChunk+1)*sizeof(*p));
000260 if( p==0 ){
000261 return SQLITE_NOMEM;
000262 }
000263 memset(&p[pGroup->nReal], 0, sizeof(p[0])*(iChunk+1-pGroup->nReal));
000264 pGroup->aReal = p;
000265 pGroup->nReal = iChunk+1;
000266 }
000267 if( pGroup->zName && pGroup->aReal[iChunk].z==0 ){
000268 char *z;
000269 int n = pGroup->nName;
000270 pGroup->aReal[iChunk].z = z = sqlite3_malloc64( n+5 );
000271 if( z==0 ){
000272 return SQLITE_NOMEM;
000273 }
000274 multiplexFilename(pGroup->zName, pGroup->nName, pGroup->flags, iChunk, z);
000275 }
000276 return SQLITE_OK;
000277 }
000278
000279 /* Translate an sqlite3_file* that is really a multiplexGroup* into
000280 ** the sqlite3_file* for the underlying original VFS.
000281 **
000282 ** For chunk 0, the pGroup->flags determines whether or not a new file
000283 ** is created if it does not already exist. For chunks 1 and higher, the
000284 ** file is created only if createFlag is 1.
000285 */
000286 static sqlite3_file *multiplexSubOpen(
000287 multiplexGroup *pGroup, /* The multiplexor group */
000288 int iChunk, /* Which chunk to open. 0==original file */
000289 int *rc, /* Result code in and out */
000290 int *pOutFlags, /* Output flags */
000291 int createFlag /* True to create if iChunk>0 */
000292 ){
000293 sqlite3_file *pSubOpen = 0;
000294 sqlite3_vfs *pOrigVfs = gMultiplex.pOrigVfs; /* Real VFS */
000295
000296 #ifdef SQLITE_ENABLE_8_3_NAMES
000297 /* If JOURNAL_8_3_OFFSET is set to (say) 400, then any overflow files are
000298 ** part of a database journal are named db.401, db.402, and so on. A
000299 ** database may therefore not grow to larger than 400 chunks. Attempting
000300 ** to open chunk 401 indicates the database is full. */
000301 if( iChunk>=SQLITE_MULTIPLEX_JOURNAL_8_3_OFFSET ){
000302 sqlite3_log(SQLITE_FULL, "multiplexed chunk overflow: %s", pGroup->zName);
000303 *rc = SQLITE_FULL;
000304 return 0;
000305 }
000306 #endif
000307
000308 *rc = multiplexSubFilename(pGroup, iChunk);
000309 if( (*rc)==SQLITE_OK && (pSubOpen = pGroup->aReal[iChunk].p)==0 ){
000310 int flags, bExists;
000311 flags = pGroup->flags;
000312 if( createFlag ){
000313 flags |= SQLITE_OPEN_CREATE;
000314 }else if( iChunk==0 ){
000315 /* Fall through */
000316 }else if( pGroup->aReal[iChunk].z==0 ){
000317 return 0;
000318 }else{
000319 *rc = pOrigVfs->xAccess(pOrigVfs, pGroup->aReal[iChunk].z,
000320 SQLITE_ACCESS_EXISTS, &bExists);
000321 if( *rc || !bExists ){
000322 if( *rc ){
000323 sqlite3_log(*rc, "multiplexor.xAccess failure on %s",
000324 pGroup->aReal[iChunk].z);
000325 }
000326 return 0;
000327 }
000328 flags &= ~SQLITE_OPEN_CREATE;
000329 }
000330 pSubOpen = sqlite3_malloc64( pOrigVfs->szOsFile );
000331 if( pSubOpen==0 ){
000332 *rc = SQLITE_IOERR_NOMEM;
000333 return 0;
000334 }
000335 pGroup->aReal[iChunk].p = pSubOpen;
000336 *rc = pOrigVfs->xOpen(pOrigVfs, pGroup->aReal[iChunk].z, pSubOpen,
000337 flags, pOutFlags);
000338 if( (*rc)!=SQLITE_OK ){
000339 sqlite3_log(*rc, "multiplexor.xOpen failure on %s",
000340 pGroup->aReal[iChunk].z);
000341 sqlite3_free(pSubOpen);
000342 pGroup->aReal[iChunk].p = 0;
000343 return 0;
000344 }
000345 }
000346 return pSubOpen;
000347 }
000348
000349 /*
000350 ** Return the size, in bytes, of chunk number iChunk. If that chunk
000351 ** does not exist, then return 0. This function does not distingish between
000352 ** non-existant files and zero-length files.
000353 */
000354 static sqlite3_int64 multiplexSubSize(
000355 multiplexGroup *pGroup, /* The multiplexor group */
000356 int iChunk, /* Which chunk to open. 0==original file */
000357 int *rc /* Result code in and out */
000358 ){
000359 sqlite3_file *pSub;
000360 sqlite3_int64 sz = 0;
000361
000362 if( *rc ) return 0;
000363 pSub = multiplexSubOpen(pGroup, iChunk, rc, NULL, 0);
000364 if( pSub==0 ) return 0;
000365 *rc = pSub->pMethods->xFileSize(pSub, &sz);
000366 return sz;
000367 }
000368
000369 /*
000370 ** This is the implementation of the multiplex_control() SQL function.
000371 */
000372 static void multiplexControlFunc(
000373 sqlite3_context *context,
000374 int argc,
000375 sqlite3_value **argv
000376 ){
000377 int rc = SQLITE_OK;
000378 sqlite3 *db = sqlite3_context_db_handle(context);
000379 int op = 0;
000380 int iVal;
000381
000382 if( !db || argc!=2 ){
000383 rc = SQLITE_ERROR;
000384 }else{
000385 /* extract params */
000386 op = sqlite3_value_int(argv[0]);
000387 iVal = sqlite3_value_int(argv[1]);
000388 /* map function op to file_control op */
000389 switch( op ){
000390 case 1:
000391 op = MULTIPLEX_CTRL_ENABLE;
000392 break;
000393 case 2:
000394 op = MULTIPLEX_CTRL_SET_CHUNK_SIZE;
000395 break;
000396 case 3:
000397 op = MULTIPLEX_CTRL_SET_MAX_CHUNKS;
000398 break;
000399 default:
000400 rc = SQLITE_NOTFOUND;
000401 break;
000402 }
000403 }
000404 if( rc==SQLITE_OK ){
000405 rc = sqlite3_file_control(db, 0, op, &iVal);
000406 }
000407 sqlite3_result_error_code(context, rc);
000408 }
000409
000410 /*
000411 ** This is the entry point to register the auto-extension for the
000412 ** multiplex_control() function.
000413 */
000414 static int multiplexFuncInit(
000415 sqlite3 *db,
000416 char **pzErrMsg,
000417 const sqlite3_api_routines *pApi
000418 ){
000419 int rc;
000420 rc = sqlite3_create_function(db, "multiplex_control", 2, SQLITE_ANY,
000421 0, multiplexControlFunc, 0, 0);
000422 return rc;
000423 }
000424
000425 /*
000426 ** Close a single sub-file in the connection group.
000427 */
000428 static void multiplexSubClose(
000429 multiplexGroup *pGroup,
000430 int iChunk,
000431 sqlite3_vfs *pOrigVfs
000432 ){
000433 sqlite3_file *pSubOpen = pGroup->aReal[iChunk].p;
000434 if( pSubOpen ){
000435 pSubOpen->pMethods->xClose(pSubOpen);
000436 if( pOrigVfs && pGroup->aReal[iChunk].z ){
000437 pOrigVfs->xDelete(pOrigVfs, pGroup->aReal[iChunk].z, 0);
000438 }
000439 sqlite3_free(pGroup->aReal[iChunk].p);
000440 }
000441 sqlite3_free(pGroup->aReal[iChunk].z);
000442 memset(&pGroup->aReal[iChunk], 0, sizeof(pGroup->aReal[iChunk]));
000443 }
000444
000445 /*
000446 ** Deallocate memory held by a multiplexGroup
000447 */
000448 static void multiplexFreeComponents(multiplexGroup *pGroup){
000449 int i;
000450 for(i=0; i<pGroup->nReal; i++){ multiplexSubClose(pGroup, i, 0); }
000451 sqlite3_free(pGroup->aReal);
000452 pGroup->aReal = 0;
000453 pGroup->nReal = 0;
000454 }
000455
000456
000457 /************************* VFS Method Wrappers *****************************/
000458
000459 /*
000460 ** This is the xOpen method used for the "multiplex" VFS.
000461 **
000462 ** Most of the work is done by the underlying original VFS. This method
000463 ** simply links the new file into the appropriate multiplex group if it is a
000464 ** file that needs to be tracked.
000465 */
000466 static int multiplexOpen(
000467 sqlite3_vfs *pVfs, /* The multiplex VFS */
000468 const char *zName, /* Name of file to be opened */
000469 sqlite3_file *pConn, /* Fill in this file descriptor */
000470 int flags, /* Flags to control the opening */
000471 int *pOutFlags /* Flags showing results of opening */
000472 ){
000473 int rc = SQLITE_OK; /* Result code */
000474 multiplexConn *pMultiplexOpen; /* The new multiplex file descriptor */
000475 multiplexGroup *pGroup = 0; /* Corresponding multiplexGroup object */
000476 sqlite3_file *pSubOpen = 0; /* Real file descriptor */
000477 sqlite3_vfs *pOrigVfs = gMultiplex.pOrigVfs; /* Real VFS */
000478 int nName = 0;
000479 int sz = 0;
000480 char *zToFree = 0;
000481
000482 UNUSED_PARAMETER(pVfs);
000483 memset(pConn, 0, pVfs->szOsFile);
000484 assert( zName || (flags & SQLITE_OPEN_DELETEONCLOSE) );
000485
000486 /* We need to create a group structure and manage
000487 ** access to this group of files.
000488 */
000489 pMultiplexOpen = (multiplexConn*)pConn;
000490
000491 if( rc==SQLITE_OK ){
000492 /* allocate space for group */
000493 nName = zName ? multiplexStrlen30(zName) : 0;
000494 sz = sizeof(multiplexGroup) /* multiplexGroup */
000495 + nName + 1; /* zName */
000496 pGroup = sqlite3_malloc64( sz );
000497 if( pGroup==0 ){
000498 rc = SQLITE_NOMEM;
000499 }
000500 }
000501
000502 if( rc==SQLITE_OK ){
000503 const char *zUri = (flags & SQLITE_OPEN_URI) ? zName : 0;
000504 /* assign pointers to extra space allocated */
000505 memset(pGroup, 0, sz);
000506 pMultiplexOpen->pGroup = pGroup;
000507 pGroup->bEnabled = (unsigned char)-1;
000508 pGroup->bTruncate = (unsigned char)sqlite3_uri_boolean(zUri, "truncate",
000509 (flags & SQLITE_OPEN_MAIN_DB)==0);
000510 pGroup->szChunk = (int)sqlite3_uri_int64(zUri, "chunksize",
000511 SQLITE_MULTIPLEX_CHUNK_SIZE);
000512 pGroup->szChunk = (pGroup->szChunk+0xffff)&~0xffff;
000513 if( zName ){
000514 char *p = (char *)&pGroup[1];
000515 pGroup->zName = p;
000516 memcpy(pGroup->zName, zName, nName+1);
000517 pGroup->nName = nName;
000518 }
000519 if( pGroup->bEnabled ){
000520 /* Make sure that the chunksize is such that the pending byte does not
000521 ** falls at the end of a chunk. A region of up to 64K following
000522 ** the pending byte is never written, so if the pending byte occurs
000523 ** near the end of a chunk, that chunk will be too small. */
000524 #ifndef SQLITE_OMIT_WSD
000525 extern int sqlite3PendingByte;
000526 #else
000527 int sqlite3PendingByte = 0x40000000;
000528 #endif
000529 while( (sqlite3PendingByte % pGroup->szChunk)>=(pGroup->szChunk-65536) ){
000530 pGroup->szChunk += 65536;
000531 }
000532 }
000533 pGroup->flags = flags;
000534 rc = multiplexSubFilename(pGroup, 1);
000535 if( rc==SQLITE_OK ){
000536 pSubOpen = multiplexSubOpen(pGroup, 0, &rc, pOutFlags, 0);
000537 if( pSubOpen==0 && rc==SQLITE_OK ) rc = SQLITE_CANTOPEN;
000538 }
000539 if( rc==SQLITE_OK ){
000540 sqlite3_int64 sz64;
000541
000542 rc = pSubOpen->pMethods->xFileSize(pSubOpen, &sz64);
000543 if( rc==SQLITE_OK && zName ){
000544 int bExists;
000545 if( flags & SQLITE_OPEN_MASTER_JOURNAL ){
000546 pGroup->bEnabled = 0;
000547 }else
000548 if( sz64==0 ){
000549 if( flags & SQLITE_OPEN_MAIN_JOURNAL ){
000550 /* If opening a main journal file and the first chunk is zero
000551 ** bytes in size, delete any subsequent chunks from the
000552 ** file-system. */
000553 int iChunk = 1;
000554 do {
000555 rc = pOrigVfs->xAccess(pOrigVfs,
000556 pGroup->aReal[iChunk].z, SQLITE_ACCESS_EXISTS, &bExists
000557 );
000558 if( rc==SQLITE_OK && bExists ){
000559 rc = pOrigVfs->xDelete(pOrigVfs, pGroup->aReal[iChunk].z, 0);
000560 if( rc==SQLITE_OK ){
000561 rc = multiplexSubFilename(pGroup, ++iChunk);
000562 }
000563 }
000564 }while( rc==SQLITE_OK && bExists );
000565 }
000566 }else{
000567 /* If the first overflow file exists and if the size of the main file
000568 ** is different from the chunk size, that means the chunk size is set
000569 ** set incorrectly. So fix it.
000570 **
000571 ** Or, if the first overflow file does not exist and the main file is
000572 ** larger than the chunk size, that means the chunk size is too small.
000573 ** But we have no way of determining the intended chunk size, so
000574 ** just disable the multiplexor all togethre.
000575 */
000576 rc = pOrigVfs->xAccess(pOrigVfs, pGroup->aReal[1].z,
000577 SQLITE_ACCESS_EXISTS, &bExists);
000578 bExists = multiplexSubSize(pGroup, 1, &rc)>0;
000579 if( rc==SQLITE_OK && bExists && sz64==(sz64&0xffff0000) && sz64>0
000580 && sz64!=pGroup->szChunk ){
000581 pGroup->szChunk = (int)sz64;
000582 }else if( rc==SQLITE_OK && !bExists && sz64>pGroup->szChunk ){
000583 pGroup->bEnabled = 0;
000584 }
000585 }
000586 }
000587 }
000588
000589 if( rc==SQLITE_OK ){
000590 if( pSubOpen->pMethods->iVersion==1 ){
000591 pMultiplexOpen->base.pMethods = &gMultiplex.sIoMethodsV1;
000592 }else{
000593 pMultiplexOpen->base.pMethods = &gMultiplex.sIoMethodsV2;
000594 }
000595 }else{
000596 multiplexFreeComponents(pGroup);
000597 sqlite3_free(pGroup);
000598 }
000599 }
000600 sqlite3_free(zToFree);
000601 return rc;
000602 }
000603
000604 /*
000605 ** This is the xDelete method used for the "multiplex" VFS.
000606 ** It attempts to delete the filename specified.
000607 */
000608 static int multiplexDelete(
000609 sqlite3_vfs *pVfs, /* The multiplex VFS */
000610 const char *zName, /* Name of file to delete */
000611 int syncDir
000612 ){
000613 int rc;
000614 sqlite3_vfs *pOrigVfs = gMultiplex.pOrigVfs; /* Real VFS */
000615 rc = pOrigVfs->xDelete(pOrigVfs, zName, syncDir);
000616 if( rc==SQLITE_OK ){
000617 /* If the main chunk was deleted successfully, also delete any subsequent
000618 ** chunks - starting with the last (highest numbered).
000619 */
000620 int nName = (int)strlen(zName);
000621 char *z;
000622 z = sqlite3_malloc64(nName + 5);
000623 if( z==0 ){
000624 rc = SQLITE_IOERR_NOMEM;
000625 }else{
000626 int iChunk = 0;
000627 int bExists;
000628 do{
000629 multiplexFilename(zName, nName, SQLITE_OPEN_MAIN_JOURNAL, ++iChunk, z);
000630 rc = pOrigVfs->xAccess(pOrigVfs, z, SQLITE_ACCESS_EXISTS, &bExists);
000631 }while( rc==SQLITE_OK && bExists );
000632 while( rc==SQLITE_OK && iChunk>1 ){
000633 multiplexFilename(zName, nName, SQLITE_OPEN_MAIN_JOURNAL, --iChunk, z);
000634 rc = pOrigVfs->xDelete(pOrigVfs, z, syncDir);
000635 }
000636 if( rc==SQLITE_OK ){
000637 iChunk = 0;
000638 do{
000639 multiplexFilename(zName, nName, SQLITE_OPEN_WAL, ++iChunk, z);
000640 rc = pOrigVfs->xAccess(pOrigVfs, z, SQLITE_ACCESS_EXISTS, &bExists);
000641 }while( rc==SQLITE_OK && bExists );
000642 while( rc==SQLITE_OK && iChunk>1 ){
000643 multiplexFilename(zName, nName, SQLITE_OPEN_WAL, --iChunk, z);
000644 rc = pOrigVfs->xDelete(pOrigVfs, z, syncDir);
000645 }
000646 }
000647 }
000648 sqlite3_free(z);
000649 }
000650 return rc;
000651 }
000652
000653 static int multiplexAccess(sqlite3_vfs *a, const char *b, int c, int *d){
000654 return gMultiplex.pOrigVfs->xAccess(gMultiplex.pOrigVfs, b, c, d);
000655 }
000656 static int multiplexFullPathname(sqlite3_vfs *a, const char *b, int c, char *d){
000657 return gMultiplex.pOrigVfs->xFullPathname(gMultiplex.pOrigVfs, b, c, d);
000658 }
000659 static void *multiplexDlOpen(sqlite3_vfs *a, const char *b){
000660 return gMultiplex.pOrigVfs->xDlOpen(gMultiplex.pOrigVfs, b);
000661 }
000662 static void multiplexDlError(sqlite3_vfs *a, int b, char *c){
000663 gMultiplex.pOrigVfs->xDlError(gMultiplex.pOrigVfs, b, c);
000664 }
000665 static void (*multiplexDlSym(sqlite3_vfs *a, void *b, const char *c))(void){
000666 return gMultiplex.pOrigVfs->xDlSym(gMultiplex.pOrigVfs, b, c);
000667 }
000668 static void multiplexDlClose(sqlite3_vfs *a, void *b){
000669 gMultiplex.pOrigVfs->xDlClose(gMultiplex.pOrigVfs, b);
000670 }
000671 static int multiplexRandomness(sqlite3_vfs *a, int b, char *c){
000672 return gMultiplex.pOrigVfs->xRandomness(gMultiplex.pOrigVfs, b, c);
000673 }
000674 static int multiplexSleep(sqlite3_vfs *a, int b){
000675 return gMultiplex.pOrigVfs->xSleep(gMultiplex.pOrigVfs, b);
000676 }
000677 static int multiplexCurrentTime(sqlite3_vfs *a, double *b){
000678 return gMultiplex.pOrigVfs->xCurrentTime(gMultiplex.pOrigVfs, b);
000679 }
000680 static int multiplexGetLastError(sqlite3_vfs *a, int b, char *c){
000681 if( gMultiplex.pOrigVfs->xGetLastError ){
000682 return gMultiplex.pOrigVfs->xGetLastError(gMultiplex.pOrigVfs, b, c);
000683 }else{
000684 return 0;
000685 }
000686 }
000687 static int multiplexCurrentTimeInt64(sqlite3_vfs *a, sqlite3_int64 *b){
000688 return gMultiplex.pOrigVfs->xCurrentTimeInt64(gMultiplex.pOrigVfs, b);
000689 }
000690
000691 /************************ I/O Method Wrappers *******************************/
000692
000693 /* xClose requests get passed through to the original VFS.
000694 ** We loop over all open chunk handles and close them.
000695 ** The group structure for this file is unlinked from
000696 ** our list of groups and freed.
000697 */
000698 static int multiplexClose(sqlite3_file *pConn){
000699 multiplexConn *p = (multiplexConn*)pConn;
000700 multiplexGroup *pGroup = p->pGroup;
000701 int rc = SQLITE_OK;
000702 multiplexFreeComponents(pGroup);
000703 sqlite3_free(pGroup);
000704 return rc;
000705 }
000706
000707 /* Pass xRead requests thru to the original VFS after
000708 ** determining the correct chunk to operate on.
000709 ** Break up reads across chunk boundaries.
000710 */
000711 static int multiplexRead(
000712 sqlite3_file *pConn,
000713 void *pBuf,
000714 int iAmt,
000715 sqlite3_int64 iOfst
000716 ){
000717 multiplexConn *p = (multiplexConn*)pConn;
000718 multiplexGroup *pGroup = p->pGroup;
000719 int rc = SQLITE_OK;
000720 if( !pGroup->bEnabled ){
000721 sqlite3_file *pSubOpen = multiplexSubOpen(pGroup, 0, &rc, NULL, 0);
000722 if( pSubOpen==0 ){
000723 rc = SQLITE_IOERR_READ;
000724 }else{
000725 rc = pSubOpen->pMethods->xRead(pSubOpen, pBuf, iAmt, iOfst);
000726 }
000727 }else{
000728 while( iAmt > 0 ){
000729 int i = (int)(iOfst / pGroup->szChunk);
000730 sqlite3_file *pSubOpen;
000731 pSubOpen = multiplexSubOpen(pGroup, i, &rc, NULL, 1);
000732 if( pSubOpen ){
000733 int extra = ((int)(iOfst % pGroup->szChunk) + iAmt) - pGroup->szChunk;
000734 if( extra<0 ) extra = 0;
000735 iAmt -= extra;
000736 rc = pSubOpen->pMethods->xRead(pSubOpen, pBuf, iAmt,
000737 iOfst % pGroup->szChunk);
000738 if( rc!=SQLITE_OK ) break;
000739 pBuf = (char *)pBuf + iAmt;
000740 iOfst += iAmt;
000741 iAmt = extra;
000742 }else{
000743 rc = SQLITE_IOERR_READ;
000744 break;
000745 }
000746 }
000747 }
000748
000749 return rc;
000750 }
000751
000752 /* Pass xWrite requests thru to the original VFS after
000753 ** determining the correct chunk to operate on.
000754 ** Break up writes across chunk boundaries.
000755 */
000756 static int multiplexWrite(
000757 sqlite3_file *pConn,
000758 const void *pBuf,
000759 int iAmt,
000760 sqlite3_int64 iOfst
000761 ){
000762 multiplexConn *p = (multiplexConn*)pConn;
000763 multiplexGroup *pGroup = p->pGroup;
000764 int rc = SQLITE_OK;
000765 if( !pGroup->bEnabled ){
000766 sqlite3_file *pSubOpen = multiplexSubOpen(pGroup, 0, &rc, NULL, 0);
000767 if( pSubOpen==0 ){
000768 rc = SQLITE_IOERR_WRITE;
000769 }else{
000770 rc = pSubOpen->pMethods->xWrite(pSubOpen, pBuf, iAmt, iOfst);
000771 }
000772 }else{
000773 while( rc==SQLITE_OK && iAmt>0 ){
000774 int i = (int)(iOfst / pGroup->szChunk);
000775 sqlite3_file *pSubOpen = multiplexSubOpen(pGroup, i, &rc, NULL, 1);
000776 if( pSubOpen ){
000777 int extra = ((int)(iOfst % pGroup->szChunk) + iAmt) -
000778 pGroup->szChunk;
000779 if( extra<0 ) extra = 0;
000780 iAmt -= extra;
000781 rc = pSubOpen->pMethods->xWrite(pSubOpen, pBuf, iAmt,
000782 iOfst % pGroup->szChunk);
000783 pBuf = (char *)pBuf + iAmt;
000784 iOfst += iAmt;
000785 iAmt = extra;
000786 }
000787 }
000788 }
000789 return rc;
000790 }
000791
000792 /* Pass xTruncate requests thru to the original VFS after
000793 ** determining the correct chunk to operate on. Delete any
000794 ** chunks above the truncate mark.
000795 */
000796 static int multiplexTruncate(sqlite3_file *pConn, sqlite3_int64 size){
000797 multiplexConn *p = (multiplexConn*)pConn;
000798 multiplexGroup *pGroup = p->pGroup;
000799 int rc = SQLITE_OK;
000800 if( !pGroup->bEnabled ){
000801 sqlite3_file *pSubOpen = multiplexSubOpen(pGroup, 0, &rc, NULL, 0);
000802 if( pSubOpen==0 ){
000803 rc = SQLITE_IOERR_TRUNCATE;
000804 }else{
000805 rc = pSubOpen->pMethods->xTruncate(pSubOpen, size);
000806 }
000807 }else{
000808 int i;
000809 int iBaseGroup = (int)(size / pGroup->szChunk);
000810 sqlite3_file *pSubOpen;
000811 sqlite3_vfs *pOrigVfs = gMultiplex.pOrigVfs; /* Real VFS */
000812 /* delete the chunks above the truncate limit */
000813 for(i = pGroup->nReal-1; i>iBaseGroup && rc==SQLITE_OK; i--){
000814 if( pGroup->bTruncate ){
000815 multiplexSubClose(pGroup, i, pOrigVfs);
000816 }else{
000817 pSubOpen = multiplexSubOpen(pGroup, i, &rc, 0, 0);
000818 if( pSubOpen ){
000819 rc = pSubOpen->pMethods->xTruncate(pSubOpen, 0);
000820 }
000821 }
000822 }
000823 if( rc==SQLITE_OK ){
000824 pSubOpen = multiplexSubOpen(pGroup, iBaseGroup, &rc, 0, 0);
000825 if( pSubOpen ){
000826 rc = pSubOpen->pMethods->xTruncate(pSubOpen, size % pGroup->szChunk);
000827 }
000828 }
000829 if( rc ) rc = SQLITE_IOERR_TRUNCATE;
000830 }
000831 return rc;
000832 }
000833
000834 /* Pass xSync requests through to the original VFS without change
000835 */
000836 static int multiplexSync(sqlite3_file *pConn, int flags){
000837 multiplexConn *p = (multiplexConn*)pConn;
000838 multiplexGroup *pGroup = p->pGroup;
000839 int rc = SQLITE_OK;
000840 int i;
000841 for(i=0; i<pGroup->nReal; i++){
000842 sqlite3_file *pSubOpen = pGroup->aReal[i].p;
000843 if( pSubOpen ){
000844 int rc2 = pSubOpen->pMethods->xSync(pSubOpen, flags);
000845 if( rc2!=SQLITE_OK ) rc = rc2;
000846 }
000847 }
000848 return rc;
000849 }
000850
000851 /* Pass xFileSize requests through to the original VFS.
000852 ** Aggregate the size of all the chunks before returning.
000853 */
000854 static int multiplexFileSize(sqlite3_file *pConn, sqlite3_int64 *pSize){
000855 multiplexConn *p = (multiplexConn*)pConn;
000856 multiplexGroup *pGroup = p->pGroup;
000857 int rc = SQLITE_OK;
000858 int i;
000859 if( !pGroup->bEnabled ){
000860 sqlite3_file *pSubOpen = multiplexSubOpen(pGroup, 0, &rc, NULL, 0);
000861 if( pSubOpen==0 ){
000862 rc = SQLITE_IOERR_FSTAT;
000863 }else{
000864 rc = pSubOpen->pMethods->xFileSize(pSubOpen, pSize);
000865 }
000866 }else{
000867 *pSize = 0;
000868 for(i=0; rc==SQLITE_OK; i++){
000869 sqlite3_int64 sz = multiplexSubSize(pGroup, i, &rc);
000870 if( sz==0 ) break;
000871 *pSize = i*(sqlite3_int64)pGroup->szChunk + sz;
000872 }
000873 }
000874 return rc;
000875 }
000876
000877 /* Pass xLock requests through to the original VFS unchanged.
000878 */
000879 static int multiplexLock(sqlite3_file *pConn, int lock){
000880 multiplexConn *p = (multiplexConn*)pConn;
000881 int rc;
000882 sqlite3_file *pSubOpen = multiplexSubOpen(p->pGroup, 0, &rc, NULL, 0);
000883 if( pSubOpen ){
000884 return pSubOpen->pMethods->xLock(pSubOpen, lock);
000885 }
000886 return SQLITE_BUSY;
000887 }
000888
000889 /* Pass xUnlock requests through to the original VFS unchanged.
000890 */
000891 static int multiplexUnlock(sqlite3_file *pConn, int lock){
000892 multiplexConn *p = (multiplexConn*)pConn;
000893 int rc;
000894 sqlite3_file *pSubOpen = multiplexSubOpen(p->pGroup, 0, &rc, NULL, 0);
000895 if( pSubOpen ){
000896 return pSubOpen->pMethods->xUnlock(pSubOpen, lock);
000897 }
000898 return SQLITE_IOERR_UNLOCK;
000899 }
000900
000901 /* Pass xCheckReservedLock requests through to the original VFS unchanged.
000902 */
000903 static int multiplexCheckReservedLock(sqlite3_file *pConn, int *pResOut){
000904 multiplexConn *p = (multiplexConn*)pConn;
000905 int rc;
000906 sqlite3_file *pSubOpen = multiplexSubOpen(p->pGroup, 0, &rc, NULL, 0);
000907 if( pSubOpen ){
000908 return pSubOpen->pMethods->xCheckReservedLock(pSubOpen, pResOut);
000909 }
000910 return SQLITE_IOERR_CHECKRESERVEDLOCK;
000911 }
000912
000913 /* Pass xFileControl requests through to the original VFS unchanged,
000914 ** except for any MULTIPLEX_CTRL_* requests here.
000915 */
000916 static int multiplexFileControl(sqlite3_file *pConn, int op, void *pArg){
000917 multiplexConn *p = (multiplexConn*)pConn;
000918 multiplexGroup *pGroup = p->pGroup;
000919 int rc = SQLITE_ERROR;
000920 sqlite3_file *pSubOpen;
000921
000922 if( !gMultiplex.isInitialized ) return SQLITE_MISUSE;
000923 switch( op ){
000924 case MULTIPLEX_CTRL_ENABLE:
000925 if( pArg ) {
000926 int bEnabled = *(int *)pArg;
000927 pGroup->bEnabled = (unsigned char)bEnabled;
000928 rc = SQLITE_OK;
000929 }
000930 break;
000931 case MULTIPLEX_CTRL_SET_CHUNK_SIZE:
000932 if( pArg ) {
000933 unsigned int szChunk = *(unsigned*)pArg;
000934 if( szChunk<1 ){
000935 rc = SQLITE_MISUSE;
000936 }else{
000937 /* Round up to nearest multiple of MAX_PAGE_SIZE. */
000938 szChunk = (szChunk + (MAX_PAGE_SIZE-1));
000939 szChunk &= ~(MAX_PAGE_SIZE-1);
000940 pGroup->szChunk = szChunk;
000941 rc = SQLITE_OK;
000942 }
000943 }
000944 break;
000945 case MULTIPLEX_CTRL_SET_MAX_CHUNKS:
000946 rc = SQLITE_OK;
000947 break;
000948 case SQLITE_FCNTL_SIZE_HINT:
000949 case SQLITE_FCNTL_CHUNK_SIZE:
000950 /* no-op these */
000951 rc = SQLITE_OK;
000952 break;
000953 case SQLITE_FCNTL_PRAGMA: {
000954 char **aFcntl = (char**)pArg;
000955 /*
000956 ** EVIDENCE-OF: R-29875-31678 The argument to the SQLITE_FCNTL_PRAGMA
000957 ** file control is an array of pointers to strings (char**) in which the
000958 ** second element of the array is the name of the pragma and the third
000959 ** element is the argument to the pragma or NULL if the pragma has no
000960 ** argument.
000961 */
000962 if( aFcntl[1] && sqlite3_stricmp(aFcntl[1],"multiplex_truncate")==0 ){
000963 if( aFcntl[2] && aFcntl[2][0] ){
000964 if( sqlite3_stricmp(aFcntl[2], "on")==0
000965 || sqlite3_stricmp(aFcntl[2], "1")==0 ){
000966 pGroup->bTruncate = 1;
000967 }else
000968 if( sqlite3_stricmp(aFcntl[2], "off")==0
000969 || sqlite3_stricmp(aFcntl[2], "0")==0 ){
000970 pGroup->bTruncate = 0;
000971 }
000972 }
000973 /* EVIDENCE-OF: R-27806-26076 The handler for an SQLITE_FCNTL_PRAGMA
000974 ** file control can optionally make the first element of the char**
000975 ** argument point to a string obtained from sqlite3_mprintf() or the
000976 ** equivalent and that string will become the result of the pragma
000977 ** or the error message if the pragma fails.
000978 */
000979 aFcntl[0] = sqlite3_mprintf(pGroup->bTruncate ? "on" : "off");
000980 rc = SQLITE_OK;
000981 break;
000982 }
000983 /* If the multiplexor does not handle the pragma, pass it through
000984 ** into the default case. */
000985 }
000986 default:
000987 pSubOpen = multiplexSubOpen(pGroup, 0, &rc, NULL, 0);
000988 if( pSubOpen ){
000989 rc = pSubOpen->pMethods->xFileControl(pSubOpen, op, pArg);
000990 if( op==SQLITE_FCNTL_VFSNAME && rc==SQLITE_OK ){
000991 *(char**)pArg = sqlite3_mprintf("multiplex/%z", *(char**)pArg);
000992 }
000993 }
000994 break;
000995 }
000996 return rc;
000997 }
000998
000999 /* Pass xSectorSize requests through to the original VFS unchanged.
001000 */
001001 static int multiplexSectorSize(sqlite3_file *pConn){
001002 multiplexConn *p = (multiplexConn*)pConn;
001003 int rc;
001004 sqlite3_file *pSubOpen = multiplexSubOpen(p->pGroup, 0, &rc, NULL, 0);
001005 if( pSubOpen && pSubOpen->pMethods->xSectorSize ){
001006 return pSubOpen->pMethods->xSectorSize(pSubOpen);
001007 }
001008 return DEFAULT_SECTOR_SIZE;
001009 }
001010
001011 /* Pass xDeviceCharacteristics requests through to the original VFS unchanged.
001012 */
001013 static int multiplexDeviceCharacteristics(sqlite3_file *pConn){
001014 multiplexConn *p = (multiplexConn*)pConn;
001015 int rc;
001016 sqlite3_file *pSubOpen = multiplexSubOpen(p->pGroup, 0, &rc, NULL, 0);
001017 if( pSubOpen ){
001018 return pSubOpen->pMethods->xDeviceCharacteristics(pSubOpen);
001019 }
001020 return 0;
001021 }
001022
001023 /* Pass xShmMap requests through to the original VFS unchanged.
001024 */
001025 static int multiplexShmMap(
001026 sqlite3_file *pConn, /* Handle open on database file */
001027 int iRegion, /* Region to retrieve */
001028 int szRegion, /* Size of regions */
001029 int bExtend, /* True to extend file if necessary */
001030 void volatile **pp /* OUT: Mapped memory */
001031 ){
001032 multiplexConn *p = (multiplexConn*)pConn;
001033 int rc;
001034 sqlite3_file *pSubOpen = multiplexSubOpen(p->pGroup, 0, &rc, NULL, 0);
001035 if( pSubOpen ){
001036 return pSubOpen->pMethods->xShmMap(pSubOpen, iRegion, szRegion, bExtend,pp);
001037 }
001038 return SQLITE_IOERR;
001039 }
001040
001041 /* Pass xShmLock requests through to the original VFS unchanged.
001042 */
001043 static int multiplexShmLock(
001044 sqlite3_file *pConn, /* Database file holding the shared memory */
001045 int ofst, /* First lock to acquire or release */
001046 int n, /* Number of locks to acquire or release */
001047 int flags /* What to do with the lock */
001048 ){
001049 multiplexConn *p = (multiplexConn*)pConn;
001050 int rc;
001051 sqlite3_file *pSubOpen = multiplexSubOpen(p->pGroup, 0, &rc, NULL, 0);
001052 if( pSubOpen ){
001053 return pSubOpen->pMethods->xShmLock(pSubOpen, ofst, n, flags);
001054 }
001055 return SQLITE_BUSY;
001056 }
001057
001058 /* Pass xShmBarrier requests through to the original VFS unchanged.
001059 */
001060 static void multiplexShmBarrier(sqlite3_file *pConn){
001061 multiplexConn *p = (multiplexConn*)pConn;
001062 int rc;
001063 sqlite3_file *pSubOpen = multiplexSubOpen(p->pGroup, 0, &rc, NULL, 0);
001064 if( pSubOpen ){
001065 pSubOpen->pMethods->xShmBarrier(pSubOpen);
001066 }
001067 }
001068
001069 /* Pass xShmUnmap requests through to the original VFS unchanged.
001070 */
001071 static int multiplexShmUnmap(sqlite3_file *pConn, int deleteFlag){
001072 multiplexConn *p = (multiplexConn*)pConn;
001073 int rc;
001074 sqlite3_file *pSubOpen = multiplexSubOpen(p->pGroup, 0, &rc, NULL, 0);
001075 if( pSubOpen ){
001076 return pSubOpen->pMethods->xShmUnmap(pSubOpen, deleteFlag);
001077 }
001078 return SQLITE_OK;
001079 }
001080
001081 /************************** Public Interfaces *****************************/
001082 /*
001083 ** CAPI: Initialize the multiplex VFS shim - sqlite3_multiplex_initialize()
001084 **
001085 ** Use the VFS named zOrigVfsName as the VFS that does the actual work.
001086 ** Use the default if zOrigVfsName==NULL.
001087 **
001088 ** The multiplex VFS shim is named "multiplex". It will become the default
001089 ** VFS if makeDefault is non-zero.
001090 **
001091 ** THIS ROUTINE IS NOT THREADSAFE. Call this routine exactly once
001092 ** during start-up.
001093 */
001094 int sqlite3_multiplex_initialize(const char *zOrigVfsName, int makeDefault){
001095 sqlite3_vfs *pOrigVfs;
001096 if( gMultiplex.isInitialized ) return SQLITE_MISUSE;
001097 pOrigVfs = sqlite3_vfs_find(zOrigVfsName);
001098 if( pOrigVfs==0 ) return SQLITE_ERROR;
001099 assert( pOrigVfs!=&gMultiplex.sThisVfs );
001100 gMultiplex.isInitialized = 1;
001101 gMultiplex.pOrigVfs = pOrigVfs;
001102 gMultiplex.sThisVfs = *pOrigVfs;
001103 gMultiplex.sThisVfs.szOsFile += sizeof(multiplexConn);
001104 gMultiplex.sThisVfs.zName = SQLITE_MULTIPLEX_VFS_NAME;
001105 gMultiplex.sThisVfs.xOpen = multiplexOpen;
001106 gMultiplex.sThisVfs.xDelete = multiplexDelete;
001107 gMultiplex.sThisVfs.xAccess = multiplexAccess;
001108 gMultiplex.sThisVfs.xFullPathname = multiplexFullPathname;
001109 gMultiplex.sThisVfs.xDlOpen = multiplexDlOpen;
001110 gMultiplex.sThisVfs.xDlError = multiplexDlError;
001111 gMultiplex.sThisVfs.xDlSym = multiplexDlSym;
001112 gMultiplex.sThisVfs.xDlClose = multiplexDlClose;
001113 gMultiplex.sThisVfs.xRandomness = multiplexRandomness;
001114 gMultiplex.sThisVfs.xSleep = multiplexSleep;
001115 gMultiplex.sThisVfs.xCurrentTime = multiplexCurrentTime;
001116 gMultiplex.sThisVfs.xGetLastError = multiplexGetLastError;
001117 gMultiplex.sThisVfs.xCurrentTimeInt64 = multiplexCurrentTimeInt64;
001118
001119 gMultiplex.sIoMethodsV1.iVersion = 1;
001120 gMultiplex.sIoMethodsV1.xClose = multiplexClose;
001121 gMultiplex.sIoMethodsV1.xRead = multiplexRead;
001122 gMultiplex.sIoMethodsV1.xWrite = multiplexWrite;
001123 gMultiplex.sIoMethodsV1.xTruncate = multiplexTruncate;
001124 gMultiplex.sIoMethodsV1.xSync = multiplexSync;
001125 gMultiplex.sIoMethodsV1.xFileSize = multiplexFileSize;
001126 gMultiplex.sIoMethodsV1.xLock = multiplexLock;
001127 gMultiplex.sIoMethodsV1.xUnlock = multiplexUnlock;
001128 gMultiplex.sIoMethodsV1.xCheckReservedLock = multiplexCheckReservedLock;
001129 gMultiplex.sIoMethodsV1.xFileControl = multiplexFileControl;
001130 gMultiplex.sIoMethodsV1.xSectorSize = multiplexSectorSize;
001131 gMultiplex.sIoMethodsV1.xDeviceCharacteristics =
001132 multiplexDeviceCharacteristics;
001133 gMultiplex.sIoMethodsV2 = gMultiplex.sIoMethodsV1;
001134 gMultiplex.sIoMethodsV2.iVersion = 2;
001135 gMultiplex.sIoMethodsV2.xShmMap = multiplexShmMap;
001136 gMultiplex.sIoMethodsV2.xShmLock = multiplexShmLock;
001137 gMultiplex.sIoMethodsV2.xShmBarrier = multiplexShmBarrier;
001138 gMultiplex.sIoMethodsV2.xShmUnmap = multiplexShmUnmap;
001139 sqlite3_vfs_register(&gMultiplex.sThisVfs, makeDefault);
001140
001141 sqlite3_auto_extension((void(*)(void))multiplexFuncInit);
001142
001143 return SQLITE_OK;
001144 }
001145
001146 /*
001147 ** CAPI: Shutdown the multiplex system - sqlite3_multiplex_shutdown()
001148 **
001149 ** All SQLite database connections must be closed before calling this
001150 ** routine.
001151 **
001152 ** THIS ROUTINE IS NOT THREADSAFE. Call this routine exactly once while
001153 ** shutting down in order to free all remaining multiplex groups.
001154 */
001155 int sqlite3_multiplex_shutdown(int eForce){
001156 int rc = SQLITE_OK;
001157 if( gMultiplex.isInitialized==0 ) return SQLITE_MISUSE;
001158 gMultiplex.isInitialized = 0;
001159 sqlite3_vfs_unregister(&gMultiplex.sThisVfs);
001160 memset(&gMultiplex, 0, sizeof(gMultiplex));
001161 return rc;
001162 }
001163
001164 /***************************** Test Code ***********************************/
001165 #ifdef SQLITE_TEST
001166 #if defined(INCLUDE_SQLITE_TCL_H)
001167 # include "sqlite_tcl.h"
001168 #else
001169 # include "tcl.h"
001170 # ifndef SQLITE_TCLAPI
001171 # define SQLITE_TCLAPI
001172 # endif
001173 #endif
001174 extern const char *sqlite3ErrName(int);
001175
001176
001177 /*
001178 ** tclcmd: sqlite3_multiplex_initialize NAME MAKEDEFAULT
001179 */
001180 static int SQLITE_TCLAPI test_multiplex_initialize(
001181 void * clientData,
001182 Tcl_Interp *interp,
001183 int objc,
001184 Tcl_Obj *CONST objv[]
001185 ){
001186 const char *zName; /* Name of new multiplex VFS */
001187 int makeDefault; /* True to make the new VFS the default */
001188 int rc; /* Value returned by multiplex_initialize() */
001189
001190 UNUSED_PARAMETER(clientData);
001191
001192 /* Process arguments */
001193 if( objc!=3 ){
001194 Tcl_WrongNumArgs(interp, 1, objv, "NAME MAKEDEFAULT");
001195 return TCL_ERROR;
001196 }
001197 zName = Tcl_GetString(objv[1]);
001198 if( Tcl_GetBooleanFromObj(interp, objv[2], &makeDefault) ) return TCL_ERROR;
001199 if( zName[0]=='\0' ) zName = 0;
001200
001201 /* Call sqlite3_multiplex_initialize() */
001202 rc = sqlite3_multiplex_initialize(zName, makeDefault);
001203 Tcl_SetResult(interp, (char *)sqlite3ErrName(rc), TCL_STATIC);
001204
001205 return TCL_OK;
001206 }
001207
001208 /*
001209 ** tclcmd: sqlite3_multiplex_shutdown
001210 */
001211 static int SQLITE_TCLAPI test_multiplex_shutdown(
001212 void * clientData,
001213 Tcl_Interp *interp,
001214 int objc,
001215 Tcl_Obj *CONST objv[]
001216 ){
001217 int rc; /* Value returned by multiplex_shutdown() */
001218
001219 UNUSED_PARAMETER(clientData);
001220
001221 if( objc==2 && strcmp(Tcl_GetString(objv[1]),"-force")!=0 ){
001222 objc = 3;
001223 }
001224 if( (objc!=1 && objc!=2) ){
001225 Tcl_WrongNumArgs(interp, 1, objv, "?-force?");
001226 return TCL_ERROR;
001227 }
001228
001229 /* Call sqlite3_multiplex_shutdown() */
001230 rc = sqlite3_multiplex_shutdown(objc==2);
001231 Tcl_SetResult(interp, (char *)sqlite3ErrName(rc), TCL_STATIC);
001232
001233 return TCL_OK;
001234 }
001235
001236 /*
001237 ** Tclcmd: test_multiplex_control HANDLE DBNAME SUB-COMMAND ?INT-VALUE?
001238 */
001239 static int SQLITE_TCLAPI test_multiplex_control(
001240 ClientData cd,
001241 Tcl_Interp *interp,
001242 int objc,
001243 Tcl_Obj *CONST objv[]
001244 ){
001245 int rc; /* Return code from file_control() */
001246 int idx; /* Index in aSub[] */
001247 Tcl_CmdInfo cmdInfo; /* Command info structure for HANDLE */
001248 sqlite3 *db; /* Underlying db handle for HANDLE */
001249 int iValue = 0;
001250 void *pArg = 0;
001251
001252 struct SubCommand {
001253 const char *zName;
001254 int op;
001255 int argtype;
001256 } aSub[] = {
001257 { "enable", MULTIPLEX_CTRL_ENABLE, 1 },
001258 { "chunk_size", MULTIPLEX_CTRL_SET_CHUNK_SIZE, 1 },
001259 { "max_chunks", MULTIPLEX_CTRL_SET_MAX_CHUNKS, 1 },
001260 { 0, 0, 0 }
001261 };
001262
001263 if( objc!=5 ){
001264 Tcl_WrongNumArgs(interp, 1, objv, "HANDLE DBNAME SUB-COMMAND INT-VALUE");
001265 return TCL_ERROR;
001266 }
001267
001268 if( 0==Tcl_GetCommandInfo(interp, Tcl_GetString(objv[1]), &cmdInfo) ){
001269 Tcl_AppendResult(interp, "expected database handle, got \"", 0);
001270 Tcl_AppendResult(interp, Tcl_GetString(objv[1]), "\"", 0);
001271 return TCL_ERROR;
001272 }else{
001273 db = *(sqlite3 **)cmdInfo.objClientData;
001274 }
001275
001276 rc = Tcl_GetIndexFromObjStruct(
001277 interp, objv[3], aSub, sizeof(aSub[0]), "sub-command", 0, &idx
001278 );
001279 if( rc!=TCL_OK ) return rc;
001280
001281 switch( aSub[idx].argtype ){
001282 case 1:
001283 if( Tcl_GetIntFromObj(interp, objv[4], &iValue) ){
001284 return TCL_ERROR;
001285 }
001286 pArg = (void *)&iValue;
001287 break;
001288 default:
001289 Tcl_WrongNumArgs(interp, 4, objv, "SUB-COMMAND");
001290 return TCL_ERROR;
001291 }
001292
001293 rc = sqlite3_file_control(db, Tcl_GetString(objv[2]), aSub[idx].op, pArg);
001294 Tcl_SetResult(interp, (char *)sqlite3ErrName(rc), TCL_STATIC);
001295 return (rc==SQLITE_OK) ? TCL_OK : TCL_ERROR;
001296 }
001297
001298 /*
001299 ** This routine registers the custom TCL commands defined in this
001300 ** module. This should be the only procedure visible from outside
001301 ** of this module.
001302 */
001303 int Sqlitemultiplex_Init(Tcl_Interp *interp){
001304 static struct {
001305 char *zName;
001306 Tcl_ObjCmdProc *xProc;
001307 } aCmd[] = {
001308 { "sqlite3_multiplex_initialize", test_multiplex_initialize },
001309 { "sqlite3_multiplex_shutdown", test_multiplex_shutdown },
001310 { "sqlite3_multiplex_control", test_multiplex_control },
001311 };
001312 int i;
001313
001314 for(i=0; i<sizeof(aCmd)/sizeof(aCmd[0]); i++){
001315 Tcl_CreateObjCommand(interp, aCmd[i].zName, aCmd[i].xProc, 0, 0);
001316 }
001317
001318 return TCL_OK;
001319 }
001320 #endif