diff options
Diffstat (limited to 'src/os_unix.c')
| -rw-r--r-- | src/os_unix.c | 41 |
1 files changed, 39 insertions, 2 deletions
diff --git a/src/os_unix.c b/src/os_unix.c index 89326783d..f37f2404e 100644 --- a/src/os_unix.c +++ b/src/os_unix.c @@ -4430,6 +4430,42 @@ static int unixShmUnmap( #endif /* #ifndef SQLITE_OMIT_WAL */ /* +** Map, remap or unmap part of the database file. +*/ +static int unixMremap( + sqlite3_file *fd, /* Main database file */ + sqlite3_int64 iOff, /* Offset to start mapping at */ + sqlite3_int64 nOld, /* Size of old mapping, or zero */ + sqlite3_int64 nNew, /* Size of new mapping, or zero */ + void **ppMap /* IN/OUT: Old/new mappings */ +){ + unixFile *p = (unixFile *)fd; /* The underlying database file */ + int rc = SQLITE_OK; /* Return code */ + void *pNew = 0; /* New mapping */ + + assert( iOff==0 ); + + if( nOld!=0 ){ + void *pOld = *ppMap; + munmap(pOld, nOld); + } + + if( nNew>0 ){ + int flags = PROT_READ; + if( (p->ctrlFlags & UNIXFILE_RDONLY)==0 ) flags |= PROT_WRITE; + nNew = (nNew+4095) & ~(i64)((1 << 12)-1); + pNew = mmap(0, nNew, flags, MAP_SHARED, p->h, iOff); + if( pNew==MAP_FAILED ){ + pNew = 0; + rc = SQLITE_IOERR; + } + } + + *ppMap = pNew; + return rc; +} + +/* ** Here ends the implementation of all sqlite3_file methods. ** ********************** End sqlite3_file Methods ******************************* @@ -4487,7 +4523,8 @@ static const sqlite3_io_methods METHOD = { \ unixShmMap, /* xShmMap */ \ unixShmLock, /* xShmLock */ \ unixShmBarrier, /* xShmBarrier */ \ - unixShmUnmap /* xShmUnmap */ \ + unixShmUnmap, /* xShmUnmap */ \ + unixMremap, /* xMremap */ \ }; \ static const sqlite3_io_methods *FINDER##Impl(const char *z, unixFile *p){ \ UNUSED_PARAMETER(z); UNUSED_PARAMETER(p); \ @@ -4504,7 +4541,7 @@ static const sqlite3_io_methods *(*const FINDER)(const char*,unixFile *p) \ IOMETHODS( posixIoFinder, /* Finder function name */ posixIoMethods, /* sqlite3_io_methods object name */ - 2, /* shared memory is enabled */ + 3, /* shared memory and mmap are enabled */ unixClose, /* xClose method */ unixLock, /* xLock method */ unixUnlock, /* xUnlock method */ |