diff options
Diffstat (limited to 'src/os_unix.c')
| -rw-r--r-- | src/os_unix.c | 80 |
1 files changed, 79 insertions, 1 deletions
diff --git a/src/os_unix.c b/src/os_unix.c index dadc3c98a..612d5c436 100644 --- a/src/os_unix.c +++ b/src/os_unix.c @@ -3141,8 +3141,14 @@ struct unixShmNode { sqlite3_mutex *mutexBuf; /* Mutex to access zBuf[] */ char *zFilename; /* Name of the mmapped file */ int h; /* Open file descriptor */ + int szMap; /* Size of the mapping into memory */ char *pMMapBuf; /* Where currently mmapped(). NULL if unmapped */ + + int pgsz; /* Size of shared-memory pages */ + int nPage; /* Size of array apPage */ + char **apPage; /* Array of mapped shared-memory pages */ + int nRef; /* Number of unixShm objects pointing to this */ unixShm *pFirst; /* All unixShm objects pointing to this */ #ifdef SQLITE_DEBUG @@ -3266,10 +3272,15 @@ static void unixShmPurge(unixFile *pFd){ unixShmNode *p = pFd->pInode->pShmNode; assert( unixMutexHeld() ); if( p && p->nRef==0 ){ + int i; assert( p->pInode==pFd->pInode ); if( p->mutex ) sqlite3_mutex_free(p->mutex); if( p->mutexBuf ) sqlite3_mutex_free(p->mutexBuf); if( p->pMMapBuf ) munmap(p->pMMapBuf, p->szMap); + for(i=0; i<p->nPage; i++){ + munmap(p->apPage[i], p->pgsz); + } + sqlite3_free(p->apPage); if( p->h>=0 ) close(p->h); p->pInode->pShmNode = 0; sqlite3_free(p); @@ -3706,6 +3717,71 @@ static void unixShmBarrier( unixLeaveMutex(); } +static int unixShmPage( + sqlite3_file *fd, /* Handle open on database file */ + int iPage, /* Page to retrieve */ + int pgsz, /* Size of pages */ + int isWrite, /* True to extend file if necessary */ + void volatile **pp /* OUT: Mapped memory */ +){ + unixFile *pDbFd = (unixFile*)fd; + unixShm *p = pDbFd->pShm; + unixShmNode *pShmNode = p->pShmNode; + int rc = SQLITE_OK; + + assert( p->hasMutexBuf==0 ); + sqlite3_mutex_enter(pShmNode->mutexBuf); + assert( pgsz==pShmNode->pgsz || pShmNode->nPage==0 ); + + if( pShmNode->nPage<=iPage ){ + char **apNew; /* New apPage[] array */ + int nByte = (iPage+1)*pgsz; /* Minimum required file size */ + struct stat sStat; + + pShmNode->pgsz = pgsz; + + /* Make sure the underlying file is large enough (or fail) */ + if( fstat(pShmNode->h, &sStat) ){ + rc = SQLITE_IOERR_SHMSIZE; + goto shmpage_out; + }else if( sStat.st_size<nByte ){ + if( !isWrite ) goto shmpage_out; + if( ftruncate(pShmNode->h, nByte) ){ + rc = SQLITE_IOERR_SHMSIZE; + goto shmpage_out; + } + } + + apNew = (char**)sqlite3_realloc(pShmNode->apPage, (iPage+1)*sizeof(char *)); + if( !apNew ){ + rc = SQLITE_IOERR_NOMEM; + goto shmpage_out; + } + pShmNode->apPage = apNew; + + while(pShmNode->nPage<=iPage){ + void *pMem = mmap( + 0, pgsz, PROT_READ|PROT_WRITE, MAP_SHARED, pShmNode->h, iPage*pgsz + ); + if( pMem==MAP_FAILED ){ + assert(0); + rc = SQLITE_IOERR; + goto shmpage_out; + } + pShmNode->apPage[pShmNode->nPage] = pMem; + pShmNode->nPage++; + } + } + +shmpage_out: + if( pShmNode->nPage>iPage ){ + *pp = pShmNode->apPage[iPage]; + }else{ + *pp = 0; + } + sqlite3_mutex_leave(pShmNode->mutexBuf); + return rc; +} #else # define unixShmOpen 0 @@ -3715,6 +3791,7 @@ static void unixShmBarrier( # define unixShmLock 0 # define unixShmBarrier 0 # define unixShmClose 0 +# define unixShmPage 0 #endif /* #ifndef SQLITE_OMIT_WAL */ /* @@ -3778,7 +3855,8 @@ static const sqlite3_io_methods METHOD = { \ unixShmRelease, /* xShmRelease */ \ unixShmLock, /* xShmLock */ \ unixShmBarrier, /* xShmBarrier */ \ - unixShmClose /* xShmClose */ \ + unixShmClose, /* xShmClose */ \ + unixShmPage /* xShmPage */ \ }; \ static const sqlite3_io_methods *FINDER##Impl(const char *z, unixFile *p){ \ UNUSED_PARAMETER(z); UNUSED_PARAMETER(p); \ |