Index: sql/vfs_wrapper.cc |
diff --git a/sql/vfs_wrapper.cc b/sql/vfs_wrapper.cc |
new file mode 100644 |
index 0000000000000000000000000000000000000000..c522be8819283448e69a2c504f9377ed1a710a1b |
--- /dev/null |
+++ b/sql/vfs_wrapper.cc |
@@ -0,0 +1,447 @@ |
+// Copyright (c) 2017 The Chromium Authors. All rights reserved. |
+// Use of this source code is governed by a BSD-style license that can be |
+// found in the LICENSE file. |
+ |
+#include "sql/vfs_wrapper.h" |
+ |
+#include <algorithm> |
+#include <string> |
+#include <vector> |
+ |
+#include "base/debug/leak_annotations.h" |
+#include "base/logging.h" |
+#include "base/memory/ptr_util.h" |
+#include "base/strings/string_piece.h" |
+ |
+#if defined(OS_MACOSX) && !defined(OS_IOS) |
+#include <CoreFoundation/CoreFoundation.h> |
+#include <CoreServices/CoreServices.h> |
+ |
+#include "base/mac/mac_util.h" |
+#include "base/mac/scoped_cftyperef.h" |
+#endif |
+ |
+namespace sql { |
+namespace { |
+ |
+// https://www.sqlite.org/vfs.html - documents the overall VFS system. |
+// |
+// https://www.sqlite.org/c3ref/vfs.html - VFS methods. This code tucks the |
+// wrapped VFS pointer into the wrapper's pAppData pointer. |
+// |
+// https://www.sqlite.org/c3ref/file.html - instance of an open file. This code |
+// allocates a VfsFile for this, which contains a pointer to the wrapped file. |
+// Idiomatic SQLite would take the wrapped VFS szOsFile and increase it to store |
+// additional data as a prefix. |
+ |
+sqlite3_vfs* GetWrappedVfs(sqlite3_vfs* wrapped_vfs) { |
+ return static_cast<sqlite3_vfs*>(wrapped_vfs->pAppData); |
+} |
+ |
+// NOTE(shess): This structure is allocated by SQLite using malloc. Do not add |
+// C++ objects, they will not be correctly constructed and destructed. Instead, |
+// manually manage a pointer to a C++ object in Open() and Close(). |
+struct VfsFile { |
+ const sqlite3_io_methods* methods; |
+ sqlite3_file* wrapped_file; |
+}; |
+ |
+VfsFile* AsVfsFile(sqlite3_file* wrapper_file) { |
+ return reinterpret_cast<VfsFile*>(wrapper_file); |
+} |
+ |
+sqlite3_file* GetWrappedFile(sqlite3_file* wrapper_file) { |
+ return AsVfsFile(wrapper_file)->wrapped_file; |
+} |
+ |
+int Close(sqlite3_file* sqlite_file) |
+{ |
+ VfsFile* file = AsVfsFile(sqlite_file); |
+ |
+ int r = file->wrapped_file->pMethods->xClose(file->wrapped_file); |
+ sqlite3_free(file->wrapped_file); |
+ memset(file, '\0', sizeof(*file)); |
+ return r; |
+} |
+ |
+int Read(sqlite3_file* sqlite_file, void* buf, int amt, sqlite3_int64 ofs) |
+{ |
+ sqlite3_file* wrapped_file = GetWrappedFile(sqlite_file); |
+ return wrapped_file->pMethods->xRead(wrapped_file, buf, amt, ofs); |
+} |
+ |
+int Write(sqlite3_file* sqlite_file, const void* buf, int amt, |
+ sqlite3_int64 ofs) |
+{ |
+ sqlite3_file* wrapped_file = GetWrappedFile(sqlite_file); |
+ return wrapped_file->pMethods->xWrite(wrapped_file, buf, amt, ofs); |
+} |
+ |
+int Truncate(sqlite3_file* sqlite_file, sqlite3_int64 size) |
+{ |
+ sqlite3_file* wrapped_file = GetWrappedFile(sqlite_file); |
+ return wrapped_file->pMethods->xTruncate(wrapped_file, size); |
+} |
+ |
+int Sync(sqlite3_file* sqlite_file, int flags) |
+{ |
+ sqlite3_file* wrapped_file = GetWrappedFile(sqlite_file); |
+ return wrapped_file->pMethods->xSync(wrapped_file, flags); |
+} |
+ |
+int FileSize(sqlite3_file* sqlite_file, sqlite3_int64* size) |
+{ |
+ sqlite3_file* wrapped_file = GetWrappedFile(sqlite_file); |
+ return wrapped_file->pMethods->xFileSize(wrapped_file, size); |
+} |
+ |
+int Lock(sqlite3_file* sqlite_file, int file_lock) |
+{ |
+ sqlite3_file* wrapped_file = GetWrappedFile(sqlite_file); |
+ return wrapped_file->pMethods->xLock(wrapped_file, file_lock); |
+} |
+ |
+int Unlock(sqlite3_file* sqlite_file, int file_lock) |
+{ |
+ sqlite3_file* wrapped_file = GetWrappedFile(sqlite_file); |
+ return wrapped_file->pMethods->xUnlock(wrapped_file, file_lock); |
+} |
+ |
+int CheckReservedLock(sqlite3_file* sqlite_file, int* result) |
+{ |
+ sqlite3_file* wrapped_file = GetWrappedFile(sqlite_file); |
+ return wrapped_file->pMethods->xCheckReservedLock(wrapped_file, result); |
+} |
+ |
+int FileControl(sqlite3_file* sqlite_file, int op, void* arg) |
+{ |
+ sqlite3_file* wrapped_file = GetWrappedFile(sqlite_file); |
+ return wrapped_file->pMethods->xFileControl(wrapped_file, op, arg); |
+} |
+ |
+int SectorSize(sqlite3_file* sqlite_file) |
+{ |
+ sqlite3_file* wrapped_file = GetWrappedFile(sqlite_file); |
+ return wrapped_file->pMethods->xSectorSize(wrapped_file); |
+} |
+ |
+int DeviceCharacteristics(sqlite3_file* sqlite_file) |
+{ |
+ sqlite3_file* wrapped_file = GetWrappedFile(sqlite_file); |
+ return wrapped_file->pMethods->xDeviceCharacteristics(wrapped_file); |
+} |
+ |
+int ShmMap(sqlite3_file *sqlite_file, int region, int size, |
+ int extend, void volatile **pp) { |
+ sqlite3_file* wrapped_file = GetWrappedFile(sqlite_file); |
+ return wrapped_file->pMethods->xShmMap( |
+ wrapped_file, region, size, extend, pp); |
+} |
+ |
+int ShmLock(sqlite3_file *sqlite_file, int ofst, int n, int flags) { |
+ sqlite3_file* wrapped_file = GetWrappedFile(sqlite_file); |
+ return wrapped_file->pMethods->xShmLock(wrapped_file, ofst, n, flags); |
+} |
+ |
+void ShmBarrier(sqlite3_file *sqlite_file) { |
+ sqlite3_file* wrapped_file = GetWrappedFile(sqlite_file); |
+ wrapped_file->pMethods->xShmBarrier(wrapped_file); |
+} |
+ |
+int ShmUnmap(sqlite3_file *sqlite_file, int del) { |
+ sqlite3_file* wrapped_file = GetWrappedFile(sqlite_file); |
+ return wrapped_file->pMethods->xShmUnmap(wrapped_file, del); |
+} |
+ |
+int Fetch(sqlite3_file *sqlite_file, sqlite3_int64 off, int amt, void **pp) { |
+ sqlite3_file* wrapped_file = GetWrappedFile(sqlite_file); |
+ return wrapped_file->pMethods->xFetch(wrapped_file, off, amt, pp); |
+} |
+ |
+int Unfetch(sqlite3_file *sqlite_file, sqlite3_int64 off, void *p) { |
+ sqlite3_file* wrapped_file = GetWrappedFile(sqlite_file); |
+ return wrapped_file->pMethods->xUnfetch(wrapped_file, off, p); |
+} |
+ |
+#if defined(OS_MACOSX) && !defined(OS_IOS) |
+// Helper to convert a POSIX path into a CoreFoundation path. |
+base::ScopedCFTypeRef<CFURLRef> CFURLRefForPath(const char* path){ |
+ base::ScopedCFTypeRef<CFStringRef> urlString( |
+ CFStringCreateWithFileSystemRepresentation(kCFAllocatorDefault, path)); |
+ base::ScopedCFTypeRef<CFURLRef> url( |
+ CFURLCreateWithFileSystemPath(kCFAllocatorDefault, urlString, |
+ kCFURLPOSIXPathStyle, FALSE)); |
+ return url; |
+} |
+#endif |
+ |
+int Open(sqlite3_vfs* vfs, const char* file_name, sqlite3_file* wrapper_file, |
+ int desired_flags, int* used_flags) { |
+ sqlite3_vfs* wrapped_vfs = GetWrappedVfs(vfs); |
+ |
+ sqlite3_file* wrapped_file = static_cast<sqlite3_file*>( |
+ sqlite3_malloc(wrapped_vfs->szOsFile)); |
+ if (!wrapped_file) |
+ return SQLITE_NOMEM; |
+ |
+ // NOTE(shess): SQLite's unixOpen() makes assumptions about the structure of |
+ // |file_name|. Do not pass a local copy, here, only the passed-in value. |
+ int rc = wrapped_vfs->xOpen(wrapped_vfs, |
+ file_name, wrapped_file, |
+ desired_flags, used_flags); |
+ if (rc != SQLITE_OK) { |
+ sqlite3_free(wrapped_file); |
+ return rc; |
+ } |
+ // NOTE(shess): Any early exit from here needs to call xClose() on |
+ // |wrapped_file|. |
+ |
+#if defined(OS_MACOSX) && !defined(OS_IOS) |
+ // When opening journal files, propagate time-machine exclusion from db. |
+ static int kJournalFlags = |
+ SQLITE_OPEN_MAIN_JOURNAL | SQLITE_OPEN_TEMP_JOURNAL | |
+ SQLITE_OPEN_SUBJOURNAL | SQLITE_OPEN_MASTER_JOURNAL; |
+ if (file_name && (desired_flags & kJournalFlags)) { |
+ // https://www.sqlite.org/c3ref/vfs.html indicates that the journal path |
+ // will have a "-suffix". |
+ size_t dash_index = base::StringPiece(file_name).rfind('-'); |
+ if (dash_index != base::StringPiece::npos) { |
+ std::string db_name(file_name, dash_index); |
+ base::ScopedCFTypeRef<CFURLRef> db_url(CFURLRefForPath(db_name.c_str())); |
+ if (CSBackupIsItemExcluded(db_url, nullptr)) { |
+ base::ScopedCFTypeRef<CFURLRef> journal_url(CFURLRefForPath(file_name)); |
+ CSBackupSetItemExcluded(journal_url, TRUE, FALSE); |
+ } |
+ } |
+ } |
+#endif |
+ |
+ // The wrapper instances must support a specific |iVersion|, but there is no |
+ // explicit guarantee that the wrapped VFS will always vend instances with the |
+ // same |iVersion| (though I believe this is always the case in practice). |
+ // Vend a distinct set of IO methods for each version supported. |
+ // |
+ // |iVersion| determines what methods SQLite may call on the instance. Having |
+ // the methods which can't be proxied return an error may cause SQLite to |
+ // operate differently than if it didn't call those methods at all. Another |
+ // solution would be to fail if the wrapped file does not have the expected |
+ // version, which may cause problems on platforms which use the system SQLite |
+ // (iOS and some Linux distros). |
+ VfsFile* file = AsVfsFile(wrapper_file); |
+ file->wrapped_file = wrapped_file; |
+ if (wrapped_file->pMethods->iVersion == 1) { |
+ static const sqlite3_io_methods io_methods = { |
+ 1, |
+ Close, |
+ Read, |
+ Write, |
+ Truncate, |
+ Sync, |
+ FileSize, |
+ Lock, |
+ Unlock, |
+ CheckReservedLock, |
+ FileControl, |
+ SectorSize, |
+ DeviceCharacteristics, |
+ }; |
+ file->methods = &io_methods; |
+ } else if (wrapped_file->pMethods->iVersion == 2) { |
+ static const sqlite3_io_methods io_methods = { |
+ 2, |
+ Close, |
+ Read, |
+ Write, |
+ Truncate, |
+ Sync, |
+ FileSize, |
+ Lock, |
+ Unlock, |
+ CheckReservedLock, |
+ FileControl, |
+ SectorSize, |
+ DeviceCharacteristics, |
+ // Methods above are valid for version 1. |
+ ShmMap, |
+ ShmLock, |
+ ShmBarrier, |
+ ShmUnmap, |
+ }; |
+ file->methods = &io_methods; |
+ } else { |
+ static const sqlite3_io_methods io_methods = { |
+ 3, |
+ Close, |
+ Read, |
+ Write, |
+ Truncate, |
+ Sync, |
+ FileSize, |
+ Lock, |
+ Unlock, |
+ CheckReservedLock, |
+ FileControl, |
+ SectorSize, |
+ DeviceCharacteristics, |
+ // Methods above are valid for version 1. |
+ ShmMap, |
+ ShmLock, |
+ ShmBarrier, |
+ ShmUnmap, |
+ // Methods above are valid for version 2. |
+ Fetch, |
+ Unfetch, |
+ }; |
+ file->methods = &io_methods; |
+ } |
+ return SQLITE_OK; |
+} |
+ |
+int Delete(sqlite3_vfs* vfs, const char* file_name, int sync_dir) { |
+ sqlite3_vfs* wrapped_vfs = GetWrappedVfs(vfs); |
+ return wrapped_vfs->xDelete(wrapped_vfs, file_name, sync_dir); |
+} |
+ |
+int Access(sqlite3_vfs* vfs, const char* file_name, int flag, int* res) { |
+ sqlite3_vfs* wrapped_vfs = GetWrappedVfs(vfs); |
+ return wrapped_vfs->xAccess(wrapped_vfs, file_name, flag, res); |
+} |
+ |
+int FullPathname(sqlite3_vfs* vfs, const char* relative_path, |
+ int buf_size, char* absolute_path) { |
+ sqlite3_vfs* wrapped_vfs = GetWrappedVfs(vfs); |
+ return wrapped_vfs->xFullPathname( |
+ wrapped_vfs, relative_path, buf_size, absolute_path); |
+} |
+ |
+void* DlOpen(sqlite3_vfs* vfs, const char* filename) { |
+ sqlite3_vfs* wrapped_vfs = GetWrappedVfs(vfs); |
+ return wrapped_vfs->xDlOpen(wrapped_vfs, filename); |
+} |
+ |
+void DlError(sqlite3_vfs* vfs, int buf_size, char* error_buffer) { |
+ sqlite3_vfs* wrapped_vfs = GetWrappedVfs(vfs); |
+ wrapped_vfs->xDlError(wrapped_vfs, buf_size, error_buffer); |
+} |
+ |
+void(*DlSym(sqlite3_vfs* vfs, void* handle, const char* sym))(void) { |
+ sqlite3_vfs* wrapped_vfs = GetWrappedVfs(vfs); |
+ return wrapped_vfs->xDlSym(wrapped_vfs, handle, sym); |
+} |
+ |
+void DlClose(sqlite3_vfs* vfs, void* handle) { |
+ sqlite3_vfs* wrapped_vfs = GetWrappedVfs(vfs); |
+ wrapped_vfs->xDlClose(wrapped_vfs, handle); |
+} |
+ |
+int Randomness(sqlite3_vfs* vfs, int buf_size, char* buffer) { |
+ sqlite3_vfs* wrapped_vfs = GetWrappedVfs(vfs); |
+ return wrapped_vfs->xRandomness(wrapped_vfs, buf_size, buffer); |
+} |
+ |
+int Sleep(sqlite3_vfs* vfs, int microseconds) { |
+ sqlite3_vfs* wrapped_vfs = GetWrappedVfs(vfs); |
+ return wrapped_vfs->xSleep(wrapped_vfs, microseconds); |
+} |
+ |
+int CurrentTime(sqlite3_vfs* vfs, double* now) { |
+ sqlite3_vfs* wrapped_vfs = GetWrappedVfs(vfs); |
+ return wrapped_vfs->xCurrentTime(wrapped_vfs, now); |
+} |
+ |
+int GetLastError(sqlite3_vfs* vfs, int e, char* s) { |
+ sqlite3_vfs* wrapped_vfs = GetWrappedVfs(vfs); |
+ return wrapped_vfs->xGetLastError(wrapped_vfs, e, s); |
+} |
+ |
+int CurrentTimeInt64(sqlite3_vfs* vfs, sqlite3_int64* now) { |
+ sqlite3_vfs* wrapped_vfs = GetWrappedVfs(vfs); |
+ return wrapped_vfs->xCurrentTimeInt64(wrapped_vfs, now); |
+} |
+ |
+int SetSystemCall(sqlite3_vfs* vfs, const char* name, |
+ sqlite3_syscall_ptr func) { |
+ sqlite3_vfs* wrapped_vfs = GetWrappedVfs(vfs); |
+ return wrapped_vfs->xSetSystemCall(wrapped_vfs, name, func); |
+} |
+ |
+sqlite3_syscall_ptr GetSystemCall(sqlite3_vfs* vfs, const char* name) { |
+ sqlite3_vfs* wrapped_vfs = GetWrappedVfs(vfs); |
+ return wrapped_vfs->xGetSystemCall(wrapped_vfs, name); |
+} |
+ |
+const char* NextSystemCall(sqlite3_vfs* vfs, const char* name) { |
+ sqlite3_vfs* wrapped_vfs = GetWrappedVfs(vfs); |
+ return wrapped_vfs->xNextSystemCall(wrapped_vfs, name); |
+} |
+ |
+} // namespace |
+ |
+sqlite3_vfs* VFSWrapper() { |
+ const char* kVFSName = "VFSWrapper"; |
+ |
+ // Return existing version if already registered. |
+ { |
+ sqlite3_vfs* vfs = sqlite3_vfs_find(kVFSName); |
+ if (vfs != nullptr) |
+ return vfs; |
+ } |
+ |
+ // Get the default VFS for this platform. If no default VFS, give up. |
+ sqlite3_vfs* wrapped_vfs = sqlite3_vfs_find(nullptr); |
+ if (!wrapped_vfs) |
+ return nullptr; |
+ |
+ std::unique_ptr<sqlite3_vfs, std::function<void(sqlite3_vfs*)>> wrapper_vfs( |
+ static_cast<sqlite3_vfs*>(sqlite3_malloc(sizeof(sqlite3_vfs))), |
+ [](sqlite3_vfs* v) { |
+ sqlite3_free(v); |
+ }); |
+ memset(wrapper_vfs.get(), '\0', sizeof(sqlite3_vfs)); |
+ |
+ // VFS implementations should always work with a SQLite that only knows about |
+ // earlier versions. |
+ wrapper_vfs->iVersion = std::min(wrapped_vfs->iVersion, 3); |
+ |
+ // Caller of xOpen() allocates this much space. |
+ wrapper_vfs->szOsFile = sizeof(VfsFile); |
+ |
+ wrapper_vfs->mxPathname = wrapped_vfs->mxPathname; |
+ wrapper_vfs->pNext = nullptr; |
+ wrapper_vfs->zName = kVFSName; |
+ |
+ // Keep a reference to the wrapped vfs for use in methods. |
+ wrapper_vfs->pAppData = wrapped_vfs; |
+ |
+ // VFS methods. |
+ wrapper_vfs->xOpen = &Open; |
+ wrapper_vfs->xDelete = &Delete; |
+ wrapper_vfs->xAccess = &Access; |
+ wrapper_vfs->xFullPathname = &FullPathname; |
+ wrapper_vfs->xDlOpen = &DlOpen; |
+ wrapper_vfs->xDlError = &DlError; |
+ wrapper_vfs->xDlSym = &DlSym; |
+ wrapper_vfs->xDlClose = &DlClose; |
+ wrapper_vfs->xRandomness = &Randomness; |
+ wrapper_vfs->xSleep = &Sleep; |
+ wrapper_vfs->xCurrentTime = &CurrentTime; |
+ wrapper_vfs->xGetLastError = &GetLastError; |
+ // The methods above are in version 1 of sqlite_vfs. |
+ // There were VFS implementations with nullptr for |xCurrentTimeInt64|. |
+ wrapper_vfs->xCurrentTimeInt64 = |
+ (wrapped_vfs->xCurrentTimeInt64 ? &CurrentTimeInt64 : nullptr); |
+ // The methods above are in version 2 of sqlite_vfs. |
+ wrapper_vfs->xSetSystemCall = &SetSystemCall; |
+ wrapper_vfs->xGetSystemCall = &GetSystemCall; |
+ wrapper_vfs->xNextSystemCall = &NextSystemCall; |
+ // The methods above are in version 3 of sqlite_vfs. |
+ |
+ if (SQLITE_OK == sqlite3_vfs_register(wrapper_vfs.get(), 0)) { |
+ ANNOTATE_LEAKING_OBJECT_PTR(wrapper_vfs.get()); |
+ wrapper_vfs.release(); |
+ } |
+ |
+ return sqlite3_vfs_find(kVFSName); |
+} |
+ |
+} // namespace sql |