diff options
Diffstat (limited to 'ext/wasm/api/sqlite3-wasm.c')
| -rw-r--r-- | ext/wasm/api/sqlite3-wasm.c | 166 |
1 files changed, 162 insertions, 4 deletions
diff --git a/ext/wasm/api/sqlite3-wasm.c b/ext/wasm/api/sqlite3-wasm.c index 6a81da3e5..eb8f58b40 100644 --- a/ext/wasm/api/sqlite3-wasm.c +++ b/ext/wasm/api/sqlite3-wasm.c @@ -1,6 +1,40 @@ +/* +** This file requires access to sqlite3.c static state in order to +** implement certain WASM-specific features. Unlike the rest of +** sqlite3.c, this file requires compiling with -std=c99 (or +** equivalent, or a later C version) because it makes use of features +** not available in C89. +*/ #include "sqlite3.c" /* +** WASM_KEEP is identical to EMSCRIPTEN_KEEPALIVE but is not +** Emscripten-specific. It explicitly includes marked functions for +** export into the target wasm file without requiring explicit listing +** of those functions in Emscripten's -sEXPORTED_FUNCTIONS=... list +** (or equivalent in other build platforms). Any function with neither +** this attribute nor which is listed as an explicit export will not +** be exported from the wasm file (but may still be used internally +** within the wasm file). +** +** The functions in this file (sqlite3-wasm.c) which require exporting +** are marked with this flag. They may also be added to any explicit +** build-time export list but need not be. All of these APIs are +** intended for use only within the project's own JS/WASM code, and +** not by client code, so an argument can be made for reducing their +** visibility by not including them in any build-time export lists. +** +** 2022-09-11: it's not yet _proven_ that this approach works in +** non-Emscripten builds. If not, such builds will need to export +** those using the --export=... wasm-ld flag (or equivalent). As of +** this writing we are tied to Emscripten for various reasons +** and cannot test the library with other build environments. +*/ +#define WASM_KEEP __attribute__((used,visibility("default"))) +// See also: +//__attribute__((export_name("theExportedName"), used, visibility("default"))) + +/* ** This function is NOT part of the sqlite3 public API. It is strictly ** for use by the sqlite project's own JS/WASM bindings. ** @@ -14,8 +48,8 @@ ** ** Returns err_code. */ -int sqlite3_wasm_db_error(sqlite3*db, int err_code, - const char *zMsg){ +WASM_KEEP +int sqlite3_wasm_db_error(sqlite3*db, int err_code, const char *zMsg){ if(0!=zMsg){ const int nMsg = sqlite3Strlen30(zMsg); sqlite3ErrorWithMsg(db, err_code, "%.*s", nMsg, zMsg); @@ -40,8 +74,9 @@ int sqlite3_wasm_db_error(sqlite3*db, int err_code, ** buffer is not large enough for the generated JSON. In debug builds ** that will trigger an assert(). */ +WASM_KEEP const char * sqlite3_wasm_enum_json(void){ - static char strBuf[1024 * 8] = {0} /* where the JSON goes */; + static char strBuf[1024 * 12] = {0} /* where the JSON goes */; int n = 0, childCount = 0, structCount = 0 /* output counters for figuring out where commas go */; char * pos = &strBuf[1] /* skip first byte for now to help protect @@ -224,7 +259,8 @@ const char * sqlite3_wasm_enum_json(void){ } _DefGroup; DefGroup(openFlags) { - /* Noting that not all of these will have any effect in WASM-space. */ + /* Noting that not all of these will have any effect in + ** WASM-space. */ DefInt(SQLITE_OPEN_READONLY); DefInt(SQLITE_OPEN_READWRITE); DefInt(SQLITE_OPEN_CREATE); @@ -287,6 +323,49 @@ const char * sqlite3_wasm_enum_json(void){ DefInt(SQLITE_IOCAP_BATCH_ATOMIC); } _DefGroup; + DefGroup(fcntl) { + DefInt(SQLITE_FCNTL_LOCKSTATE); + DefInt(SQLITE_FCNTL_GET_LOCKPROXYFILE); + DefInt(SQLITE_FCNTL_SET_LOCKPROXYFILE); + DefInt(SQLITE_FCNTL_LAST_ERRNO); + DefInt(SQLITE_FCNTL_SIZE_HINT); + DefInt(SQLITE_FCNTL_CHUNK_SIZE); + DefInt(SQLITE_FCNTL_FILE_POINTER); + DefInt(SQLITE_FCNTL_SYNC_OMITTED); + DefInt(SQLITE_FCNTL_WIN32_AV_RETRY); + DefInt(SQLITE_FCNTL_PERSIST_WAL); + DefInt(SQLITE_FCNTL_OVERWRITE); + DefInt(SQLITE_FCNTL_VFSNAME); + DefInt(SQLITE_FCNTL_POWERSAFE_OVERWRITE); + DefInt(SQLITE_FCNTL_PRAGMA); + DefInt(SQLITE_FCNTL_BUSYHANDLER); + DefInt(SQLITE_FCNTL_TEMPFILENAME); + DefInt(SQLITE_FCNTL_MMAP_SIZE); + DefInt(SQLITE_FCNTL_TRACE); + DefInt(SQLITE_FCNTL_HAS_MOVED); + DefInt(SQLITE_FCNTL_SYNC); + DefInt(SQLITE_FCNTL_COMMIT_PHASETWO); + DefInt(SQLITE_FCNTL_WIN32_SET_HANDLE); + DefInt(SQLITE_FCNTL_WAL_BLOCK); + DefInt(SQLITE_FCNTL_ZIPVFS); + DefInt(SQLITE_FCNTL_RBU); + DefInt(SQLITE_FCNTL_VFS_POINTER); + DefInt(SQLITE_FCNTL_JOURNAL_POINTER); + DefInt(SQLITE_FCNTL_WIN32_GET_HANDLE); + DefInt(SQLITE_FCNTL_PDB); + DefInt(SQLITE_FCNTL_BEGIN_ATOMIC_WRITE); + DefInt(SQLITE_FCNTL_COMMIT_ATOMIC_WRITE); + DefInt(SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE); + DefInt(SQLITE_FCNTL_LOCK_TIMEOUT); + DefInt(SQLITE_FCNTL_DATA_VERSION); + DefInt(SQLITE_FCNTL_SIZE_LIMIT); + DefInt(SQLITE_FCNTL_CKPT_DONE); + DefInt(SQLITE_FCNTL_RESERVE_BYTES); + DefInt(SQLITE_FCNTL_CKPT_START); + DefInt(SQLITE_FCNTL_EXTERNAL_READER); + DefInt(SQLITE_FCNTL_CKSM_FILE); + } _DefGroup; + DefGroup(access){ DefInt(SQLITE_ACCESS_EXISTS); DefInt(SQLITE_ACCESS_READWRITE); @@ -411,3 +490,82 @@ const char * sqlite3_wasm_enum_json(void){ #undef outf #undef lenCheck } + +/* +** This function is NOT part of the sqlite3 public API. It is strictly +** for use by the sqlite project's own JS/WASM bindings. +** +** This function invokes the xDelete method of the default VFS, +** passing on the given filename. If zName is NULL, no default VFS is +** found, or it has no xDelete method, SQLITE_MISUSE is returned, else +** the result of the xDelete() call is returned. +*/ +WASM_KEEP +int sqlite3_wasm_vfs_unlink(const char * zName){ + int rc = SQLITE_MISUSE /* ??? */; + sqlite3_vfs * const pVfs = sqlite3_vfs_find(0); + if( zName && pVfs && pVfs->xDelete ){ + rc = pVfs->xDelete(pVfs, zName, 1); + } + return rc; +} + +#if defined(__EMSCRIPTEN__) && defined(SQLITE_WASM_WASMFS) +#include <emscripten/wasmfs.h> +#include <emscripten/console.h> + +/* +** This function is NOT part of the sqlite3 public API. It is strictly +** for use by the sqlite project's own JS/WASM bindings, specifically +** only when building with Emscripten's WASMFS support. +** +** This function should only be called if the JS side detects the +** existence of the Origin-Private FileSystem (OPFS) APIs in the +** client. The first time it is called, this function instantiates a +** WASMFS backend impl for OPFS. On success, subsequent calls are +** no-ops. +** +** This function may be passed a "mount point" name, which must have a +** leading "/" and is currently restricted to a single path component, +** e.g. "/foo" is legal but "/foo/" and "/foo/bar" are not. If it is +** NULL or empty, it defaults to "/persistent". +** +** Returns 0 on success, SQLITE_NOMEM if instantiation of the backend +** object fails, SQLITE_IOERR if mkdir() of the zMountPoint dir in +** the virtual FS fails. In builds compiled without SQLITE_WASM_WASMFS +** defined, SQLITE_NOTFOUND is returned without side effects. +*/ +WASM_KEEP +int sqlite3_wasm_init_wasmfs(const char *zMountPoint){ + static backend_t pOpfs = 0; + if( !zMountPoint || !*zMountPoint ) zMountPoint = "/persistent"; + if( !pOpfs ){ + pOpfs = wasmfs_create_opfs_backend(); + if( pOpfs ){ + emscripten_console_log("Created WASMFS OPFS backend."); + } + } + /** It's not enough to instantiate the backend. We have to create a + mountpoint in the VFS and attach the backend to it. */ + if( pOpfs && 0!=access(zMountPoint, F_OK) ){ + /* mkdir() simply hangs when called from fiddle app. Cause is + not yet determined but the hypothesis is an init-order + issue. */ + /* Note that this check and is not robust but it will + hypothetically suffice for the transient wasm-based virtual + filesystem we're currently running in. */ + const int rc = wasmfs_create_directory(zMountPoint, 0777, pOpfs); + emscripten_console_logf("OPFS mkdir(%s) rc=%d", zMountPoint, rc); + if(rc) return SQLITE_IOERR; + } + return pOpfs ? 0 : SQLITE_NOMEM; +} +#else +WASM_KEEP +int sqlite3_wasm_init_wasmfs(void){ + return SQLITE_NOTFOUND; +} +#endif /* __EMSCRIPTEN__ && SQLITE_WASM_WASMFS */ + + +#undef WASM_KEEP |