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Diffstat (limited to '')
| -rw-r--r-- | storage/TelemetryVFS.cpp | 740 |
1 files changed, 740 insertions, 0 deletions
diff --git a/storage/TelemetryVFS.cpp b/storage/TelemetryVFS.cpp new file mode 100644 index 0000000000..51a01db004 --- /dev/null +++ b/storage/TelemetryVFS.cpp @@ -0,0 +1,740 @@ +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- + * vim: sw=2 ts=2 et lcs=trail\:.,tab\:>~ : + * This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#include <string.h> +#include "mozilla/Telemetry.h" +#include "sqlite3.h" +#include "nsThreadUtils.h" +#include "mozilla/dom/quota/PersistenceType.h" +#include "mozilla/dom/quota/QuotaManager.h" +#include "mozilla/dom/quota/QuotaObject.h" +#include "mozilla/net/IOActivityMonitor.h" +#include "mozilla/IOInterposer.h" +#include "nsEscape.h" +#include "mozilla/StaticPrefs_storage.h" + +#ifdef XP_WIN +# include "mozilla/StaticPrefs_dom.h" +#endif + +// The last VFS version for which this file has been updated. +#define LAST_KNOWN_VFS_VERSION 3 + +// The last io_methods version for which this file has been updated. +#define LAST_KNOWN_IOMETHODS_VERSION 3 + +namespace { + +using namespace mozilla; +using namespace mozilla::dom::quota; +using namespace mozilla::net; + +struct Histograms { + const char* name; + const Telemetry::HistogramID readB; + const Telemetry::HistogramID writeB; + const Telemetry::HistogramID readMS; + const Telemetry::HistogramID writeMS; + const Telemetry::HistogramID syncMS; +}; + +#define SQLITE_TELEMETRY(FILENAME, HGRAM) \ + { \ + FILENAME, Telemetry::MOZ_SQLITE_##HGRAM##_READ_B, \ + Telemetry::MOZ_SQLITE_##HGRAM##_WRITE_B, \ + Telemetry::MOZ_SQLITE_##HGRAM##_READ_MS, \ + Telemetry::MOZ_SQLITE_##HGRAM##_WRITE_MS, \ + Telemetry::MOZ_SQLITE_##HGRAM##_SYNC_MS \ + } + +Histograms gHistograms[] = {SQLITE_TELEMETRY("places.sqlite", PLACES), + SQLITE_TELEMETRY("cookies.sqlite", COOKIES), + SQLITE_TELEMETRY("webappsstore.sqlite", WEBAPPS), + SQLITE_TELEMETRY(nullptr, OTHER)}; +#undef SQLITE_TELEMETRY + +/** RAII class for measuring how long io takes on/off main thread + */ +class IOThreadAutoTimer { + public: + /** + * IOThreadAutoTimer measures time spent in IO. Additionally it + * automatically determines whether IO is happening on the main + * thread and picks an appropriate histogram. + * + * @param id takes a telemetry histogram id. The id+1 must be an + * equivalent histogram for the main thread. Eg, MOZ_SQLITE_OPEN_MS + * is followed by MOZ_SQLITE_OPEN_MAIN_THREAD_MS. + * + * @param aOp optionally takes an IO operation to report through the + * IOInterposer. Filename will be reported as NULL, and reference will be + * either "sqlite-mainthread" or "sqlite-otherthread". + */ + explicit IOThreadAutoTimer( + Telemetry::HistogramID aId, + IOInterposeObserver::Operation aOp = IOInterposeObserver::OpNone) + : start(TimeStamp::Now()), + id(aId) +#if !defined(XP_WIN) + , + op(aOp) +#endif + { + } + + /** + * This constructor is for when we want to report an operation to + * IOInterposer but do not require a telemetry probe. + * + * @param aOp IO Operation to report through the IOInterposer. + */ + explicit IOThreadAutoTimer(IOInterposeObserver::Operation aOp) + : start(TimeStamp::Now()), + id(Telemetry::HistogramCount) +#if !defined(XP_WIN) + , + op(aOp) +#endif + { + } + + ~IOThreadAutoTimer() { + TimeStamp end(TimeStamp::Now()); + uint32_t mainThread = NS_IsMainThread() ? 1 : 0; + if (id != Telemetry::HistogramCount) { + Telemetry::AccumulateTimeDelta( + static_cast<Telemetry::HistogramID>(id + mainThread), start, end); + } + // We don't report SQLite I/O on Windows because we have a comprehensive + // mechanism for intercepting I/O on that platform that captures a superset + // of the data captured here. +#if !defined(XP_WIN) + if (IOInterposer::IsObservedOperation(op)) { + const char* main_ref = "sqlite-mainthread"; + const char* other_ref = "sqlite-otherthread"; + + // Create observation + IOInterposeObserver::Observation ob(op, start, end, + (mainThread ? main_ref : other_ref)); + // Report observation + IOInterposer::Report(ob); + } +#endif /* !defined(XP_WIN) */ + } + + private: + const TimeStamp start; + const Telemetry::HistogramID id; +#if !defined(XP_WIN) + IOInterposeObserver::Operation op; +#endif +}; + +struct telemetry_file { + // Base class. Must be first + sqlite3_file base; + + // histograms pertaining to this file + Histograms* histograms; + + // quota object for this file + RefPtr<QuotaObject> quotaObject; + + // The chunk size for this file. See the documentation for + // sqlite3_file_control() and FCNTL_CHUNK_SIZE. + int fileChunkSize; + + // The filename + char* location; + + // This contains the vfs that actually does work + sqlite3_file pReal[1]; +}; + +already_AddRefed<QuotaObject> GetQuotaObjectFromName(const char* zName) { + MOZ_ASSERT(zName); + + const char* directoryLockIdParam = + sqlite3_uri_parameter(zName, "directoryLockId"); + if (!directoryLockIdParam) { + return nullptr; + } + + nsresult rv; + const int64_t directoryLockId = + nsDependentCString(directoryLockIdParam).ToInteger64(&rv); + MOZ_RELEASE_ASSERT(NS_SUCCEEDED(rv)); + + QuotaManager* quotaManager = QuotaManager::Get(); + MOZ_ASSERT(quotaManager); + + return quotaManager->GetQuotaObject(directoryLockId, + NS_ConvertUTF8toUTF16(zName)); +} + +void MaybeEstablishQuotaControl(const char* zName, telemetry_file* pFile, + int flags) { + MOZ_ASSERT(pFile); + MOZ_ASSERT(!pFile->quotaObject); + + if (!(flags & (SQLITE_OPEN_URI | SQLITE_OPEN_WAL))) { + return; + } + pFile->quotaObject = GetQuotaObjectFromName(zName); +} + +/* +** Close a telemetry_file. +*/ +int xClose(sqlite3_file* pFile) { + telemetry_file* p = (telemetry_file*)pFile; + int rc; + { // Scope for IOThreadAutoTimer + IOThreadAutoTimer ioTimer(IOInterposeObserver::OpClose); + rc = p->pReal->pMethods->xClose(p->pReal); + } + if (rc == SQLITE_OK) { + delete p->base.pMethods; + p->base.pMethods = nullptr; + p->quotaObject = nullptr; + delete[] p->location; +#ifdef DEBUG + p->fileChunkSize = 0; +#endif + } + return rc; +} + +/* +** Read data from a telemetry_file. +*/ +int xRead(sqlite3_file* pFile, void* zBuf, int iAmt, sqlite_int64 iOfst) { + telemetry_file* p = (telemetry_file*)pFile; + IOThreadAutoTimer ioTimer(p->histograms->readMS, IOInterposeObserver::OpRead); + int rc; + rc = p->pReal->pMethods->xRead(p->pReal, zBuf, iAmt, iOfst); + if (rc == SQLITE_OK && IOActivityMonitor::IsActive()) { + IOActivityMonitor::Read(nsDependentCString(p->location), iAmt); + } + // sqlite likes to read from empty files, this is normal, ignore it. + if (rc != SQLITE_IOERR_SHORT_READ) + Telemetry::Accumulate(p->histograms->readB, rc == SQLITE_OK ? iAmt : 0); + return rc; +} + +/* +** Return the current file-size of a telemetry_file. +*/ +int xFileSize(sqlite3_file* pFile, sqlite_int64* pSize) { + IOThreadAutoTimer ioTimer(IOInterposeObserver::OpStat); + telemetry_file* p = (telemetry_file*)pFile; + int rc; + rc = p->pReal->pMethods->xFileSize(p->pReal, pSize); + return rc; +} + +/* +** Write data to a telemetry_file. +*/ +int xWrite(sqlite3_file* pFile, const void* zBuf, int iAmt, + sqlite_int64 iOfst) { + telemetry_file* p = (telemetry_file*)pFile; + IOThreadAutoTimer ioTimer(p->histograms->writeMS, + IOInterposeObserver::OpWrite); + int rc; + if (p->quotaObject) { + MOZ_ASSERT(INT64_MAX - iOfst >= iAmt); + if (!p->quotaObject->MaybeUpdateSize(iOfst + iAmt, /* aTruncate */ false)) { + return SQLITE_FULL; + } + } + rc = p->pReal->pMethods->xWrite(p->pReal, zBuf, iAmt, iOfst); + if (rc == SQLITE_OK && IOActivityMonitor::IsActive()) { + IOActivityMonitor::Write(nsDependentCString(p->location), iAmt); + } + + Telemetry::Accumulate(p->histograms->writeB, rc == SQLITE_OK ? iAmt : 0); + if (p->quotaObject && rc != SQLITE_OK) { + NS_WARNING( + "xWrite failed on a quota-controlled file, attempting to " + "update its current size..."); + sqlite_int64 currentSize; + if (xFileSize(pFile, ¤tSize) == SQLITE_OK) { + DebugOnly<bool> res = + p->quotaObject->MaybeUpdateSize(currentSize, /* aTruncate */ true); + MOZ_ASSERT(res); + } + } + return rc; +} + +/* +** Truncate a telemetry_file. +*/ +int xTruncate(sqlite3_file* pFile, sqlite_int64 size) { + IOThreadAutoTimer ioTimer(Telemetry::MOZ_SQLITE_TRUNCATE_MS); + telemetry_file* p = (telemetry_file*)pFile; + int rc; + Telemetry::AutoTimer<Telemetry::MOZ_SQLITE_TRUNCATE_MS> timer; + if (p->quotaObject) { + if (p->fileChunkSize > 0) { + // Round up to the smallest multiple of the chunk size that will hold all + // the data. + size = + ((size + p->fileChunkSize - 1) / p->fileChunkSize) * p->fileChunkSize; + } + if (!p->quotaObject->MaybeUpdateSize(size, /* aTruncate */ true)) { + return SQLITE_FULL; + } + } + rc = p->pReal->pMethods->xTruncate(p->pReal, size); + if (p->quotaObject) { + if (rc == SQLITE_OK) { +#ifdef DEBUG + // Make sure xTruncate set the size exactly as we calculated above. + sqlite_int64 newSize; + MOZ_ASSERT(xFileSize(pFile, &newSize) == SQLITE_OK); + MOZ_ASSERT(newSize == size); +#endif + } else { + NS_WARNING( + "xTruncate failed on a quota-controlled file, attempting to " + "update its current size..."); + if (xFileSize(pFile, &size) == SQLITE_OK) { + DebugOnly<bool> res = + p->quotaObject->MaybeUpdateSize(size, /* aTruncate */ true); + MOZ_ASSERT(res); + } + } + } + return rc; +} + +/* +** Sync a telemetry_file. +*/ +int xSync(sqlite3_file* pFile, int flags) { + telemetry_file* p = (telemetry_file*)pFile; + IOThreadAutoTimer ioTimer(p->histograms->syncMS, + IOInterposeObserver::OpFSync); + return p->pReal->pMethods->xSync(p->pReal, flags); +} + +/* +** Lock a telemetry_file. +*/ +int xLock(sqlite3_file* pFile, int eLock) { + telemetry_file* p = (telemetry_file*)pFile; + int rc; + rc = p->pReal->pMethods->xLock(p->pReal, eLock); + return rc; +} + +/* +** Unlock a telemetry_file. +*/ +int xUnlock(sqlite3_file* pFile, int eLock) { + telemetry_file* p = (telemetry_file*)pFile; + int rc; + rc = p->pReal->pMethods->xUnlock(p->pReal, eLock); + return rc; +} + +/* +** Check if another file-handle holds a RESERVED lock on a telemetry_file. +*/ +int xCheckReservedLock(sqlite3_file* pFile, int* pResOut) { + telemetry_file* p = (telemetry_file*)pFile; + int rc = p->pReal->pMethods->xCheckReservedLock(p->pReal, pResOut); + return rc; +} + +/* +** File control method. For custom operations on a telemetry_file. +*/ +int xFileControl(sqlite3_file* pFile, int op, void* pArg) { + telemetry_file* p = (telemetry_file*)pFile; + int rc; + // Hook SQLITE_FCNTL_SIZE_HINT for quota-controlled files and do the necessary + // work before passing to the SQLite VFS. + if (op == SQLITE_FCNTL_SIZE_HINT && p->quotaObject) { + sqlite3_int64 hintSize = *static_cast<sqlite3_int64*>(pArg); + sqlite3_int64 currentSize; + rc = xFileSize(pFile, ¤tSize); + if (rc != SQLITE_OK) { + return rc; + } + if (hintSize > currentSize) { + rc = xTruncate(pFile, hintSize); + if (rc != SQLITE_OK) { + return rc; + } + } + } + rc = p->pReal->pMethods->xFileControl(p->pReal, op, pArg); + // Grab the file chunk size after the SQLite VFS has approved. + if (op == SQLITE_FCNTL_CHUNK_SIZE && rc == SQLITE_OK) { + p->fileChunkSize = *static_cast<int*>(pArg); + } +#ifdef DEBUG + if (op == SQLITE_FCNTL_SIZE_HINT && p->quotaObject && rc == SQLITE_OK) { + sqlite3_int64 hintSize = *static_cast<sqlite3_int64*>(pArg); + if (p->fileChunkSize > 0) { + hintSize = ((hintSize + p->fileChunkSize - 1) / p->fileChunkSize) * + p->fileChunkSize; + } + sqlite3_int64 currentSize; + MOZ_ASSERT(xFileSize(pFile, ¤tSize) == SQLITE_OK); + MOZ_ASSERT(currentSize >= hintSize); + } +#endif + return rc; +} + +/* +** Return the sector-size in bytes for a telemetry_file. +*/ +int xSectorSize(sqlite3_file* pFile) { + telemetry_file* p = (telemetry_file*)pFile; + int rc; + rc = p->pReal->pMethods->xSectorSize(p->pReal); + return rc; +} + +/* +** Return the device characteristic flags supported by a telemetry_file. +*/ +int xDeviceCharacteristics(sqlite3_file* pFile) { + telemetry_file* p = (telemetry_file*)pFile; + int rc; + rc = p->pReal->pMethods->xDeviceCharacteristics(p->pReal); + return rc; +} + +/* +** Shared-memory operations. +*/ +int xShmLock(sqlite3_file* pFile, int ofst, int n, int flags) { + telemetry_file* p = (telemetry_file*)pFile; + return p->pReal->pMethods->xShmLock(p->pReal, ofst, n, flags); +} + +int xShmMap(sqlite3_file* pFile, int iRegion, int szRegion, int isWrite, + void volatile** pp) { + telemetry_file* p = (telemetry_file*)pFile; + int rc; + rc = p->pReal->pMethods->xShmMap(p->pReal, iRegion, szRegion, isWrite, pp); + return rc; +} + +void xShmBarrier(sqlite3_file* pFile) { + telemetry_file* p = (telemetry_file*)pFile; + p->pReal->pMethods->xShmBarrier(p->pReal); +} + +int xShmUnmap(sqlite3_file* pFile, int delFlag) { + telemetry_file* p = (telemetry_file*)pFile; + int rc; + rc = p->pReal->pMethods->xShmUnmap(p->pReal, delFlag); + return rc; +} + +int xFetch(sqlite3_file* pFile, sqlite3_int64 iOff, int iAmt, void** pp) { + telemetry_file* p = (telemetry_file*)pFile; + MOZ_ASSERT(p->pReal->pMethods->iVersion >= 3); + return p->pReal->pMethods->xFetch(p->pReal, iOff, iAmt, pp); +} + +int xUnfetch(sqlite3_file* pFile, sqlite3_int64 iOff, void* pResOut) { + telemetry_file* p = (telemetry_file*)pFile; + MOZ_ASSERT(p->pReal->pMethods->iVersion >= 3); + return p->pReal->pMethods->xUnfetch(p->pReal, iOff, pResOut); +} + +int xOpen(sqlite3_vfs* vfs, const char* zName, sqlite3_file* pFile, int flags, + int* pOutFlags) { + IOThreadAutoTimer ioTimer(Telemetry::MOZ_SQLITE_OPEN_MS, + IOInterposeObserver::OpCreateOrOpen); + Telemetry::AutoTimer<Telemetry::MOZ_SQLITE_OPEN_MS> timer; + sqlite3_vfs* orig_vfs = static_cast<sqlite3_vfs*>(vfs->pAppData); + int rc; + telemetry_file* p = (telemetry_file*)pFile; + Histograms* h = nullptr; + // check if the filename is one we are probing for + for (size_t i = 0; i < sizeof(gHistograms) / sizeof(gHistograms[0]); i++) { + h = &gHistograms[i]; + // last probe is the fallback probe + if (!h->name) break; + if (!zName) continue; + const char* match = strstr(zName, h->name); + if (!match) continue; + char c = match[strlen(h->name)]; + // include -wal/-journal too + if (!c || c == '-') break; + } + p->histograms = h; + + MaybeEstablishQuotaControl(zName, p, flags); + + rc = orig_vfs->xOpen(orig_vfs, zName, p->pReal, flags, pOutFlags); + if (rc != SQLITE_OK) return rc; + + if (zName) { + p->location = new char[7 + strlen(zName) + 1]; + strcpy(p->location, "file://"); + strcpy(p->location + 7, zName); + } else { + p->location = new char[8]; + strcpy(p->location, "file://"); + } + + if (p->pReal->pMethods) { + sqlite3_io_methods* pNew = new sqlite3_io_methods; + const sqlite3_io_methods* pSub = p->pReal->pMethods; + memset(pNew, 0, sizeof(*pNew)); + // If the io_methods version is higher than the last known one, you should + // update this VFS adding appropriate IO methods for any methods added in + // the version change. + pNew->iVersion = pSub->iVersion; + MOZ_ASSERT(pNew->iVersion <= LAST_KNOWN_IOMETHODS_VERSION); + pNew->xClose = xClose; + pNew->xRead = xRead; + pNew->xWrite = xWrite; + pNew->xTruncate = xTruncate; + pNew->xSync = xSync; + pNew->xFileSize = xFileSize; + pNew->xLock = xLock; + pNew->xUnlock = xUnlock; + pNew->xCheckReservedLock = xCheckReservedLock; + pNew->xFileControl = xFileControl; + pNew->xSectorSize = xSectorSize; + pNew->xDeviceCharacteristics = xDeviceCharacteristics; + if (pNew->iVersion >= 2) { + // Methods added in version 2. + pNew->xShmMap = pSub->xShmMap ? xShmMap : 0; + pNew->xShmLock = pSub->xShmLock ? xShmLock : 0; + pNew->xShmBarrier = pSub->xShmBarrier ? xShmBarrier : 0; + pNew->xShmUnmap = pSub->xShmUnmap ? xShmUnmap : 0; + } + if (pNew->iVersion >= 3) { + // Methods added in version 3. + // SQLite 3.7.17 calls these methods without checking for nullptr first, + // so we always define them. Verify that we're not going to call + // nullptrs, though. + MOZ_ASSERT(pSub->xFetch); + pNew->xFetch = xFetch; + MOZ_ASSERT(pSub->xUnfetch); + pNew->xUnfetch = xUnfetch; + } + pFile->pMethods = pNew; + } + return rc; +} + +int xDelete(sqlite3_vfs* vfs, const char* zName, int syncDir) { + sqlite3_vfs* orig_vfs = static_cast<sqlite3_vfs*>(vfs->pAppData); + int rc; + RefPtr<QuotaObject> quotaObject; + + if (StringEndsWith(nsDependentCString(zName), "-wal"_ns)) { + quotaObject = GetQuotaObjectFromName(zName); + } + + rc = orig_vfs->xDelete(orig_vfs, zName, syncDir); + if (rc == SQLITE_OK && quotaObject) { + MOZ_ALWAYS_TRUE(quotaObject->MaybeUpdateSize(0, /* aTruncate */ true)); + } + + return rc; +} + +int xAccess(sqlite3_vfs* vfs, const char* zName, int flags, int* pResOut) { + sqlite3_vfs* orig_vfs = static_cast<sqlite3_vfs*>(vfs->pAppData); + return orig_vfs->xAccess(orig_vfs, zName, flags, pResOut); +} + +int xFullPathname(sqlite3_vfs* vfs, const char* zName, int nOut, char* zOut) { +#if defined(XP_WIN) + // SQLite uses GetFullPathnameW which also normailizes file path. If a file + // component ends with a dot, it would be removed. However, it's not desired. + // + // And that would result SQLite uses wrong database and quotaObject. + // Note that we are safe to avoid the GetFullPathnameW call for \\?\ prefixed + // paths. + // And note that this hack will be removed once the issue is fixed directly in + // SQLite. + + // zName that starts with "//?/" is the case when a file URI was passed and + // zName that starts with "\\?\" is the case when a normal path was passed + // (not file URI). + if (StaticPrefs::dom_quotaManager_overrideXFullPathname() && + ((zName[0] == '/' && zName[1] == '/' && zName[2] == '?' && + zName[3] == '/') || + (zName[0] == '\\' && zName[1] == '\\' && zName[2] == '?' && + zName[3] == '\\'))) { + MOZ_ASSERT(nOut >= vfs->mxPathname); + MOZ_ASSERT(static_cast<size_t>(nOut) > strlen(zName)); + + size_t index = 0; + while (zName[index] != '\0') { + if (zName[index] == '/') { + zOut[index] = '\\'; + } else { + zOut[index] = zName[index]; + } + + index++; + } + zOut[index] = '\0'; + + return SQLITE_OK; + } +#endif + + sqlite3_vfs* orig_vfs = static_cast<sqlite3_vfs*>(vfs->pAppData); + return orig_vfs->xFullPathname(orig_vfs, zName, nOut, zOut); +} + +void* xDlOpen(sqlite3_vfs* vfs, const char* zFilename) { + sqlite3_vfs* orig_vfs = static_cast<sqlite3_vfs*>(vfs->pAppData); + return orig_vfs->xDlOpen(orig_vfs, zFilename); +} + +void xDlError(sqlite3_vfs* vfs, int nByte, char* zErrMsg) { + sqlite3_vfs* orig_vfs = static_cast<sqlite3_vfs*>(vfs->pAppData); + orig_vfs->xDlError(orig_vfs, nByte, zErrMsg); +} + +void (*xDlSym(sqlite3_vfs* vfs, void* pHdle, const char* zSym))(void) { + sqlite3_vfs* orig_vfs = static_cast<sqlite3_vfs*>(vfs->pAppData); + return orig_vfs->xDlSym(orig_vfs, pHdle, zSym); +} + +void xDlClose(sqlite3_vfs* vfs, void* pHandle) { + sqlite3_vfs* orig_vfs = static_cast<sqlite3_vfs*>(vfs->pAppData); + orig_vfs->xDlClose(orig_vfs, pHandle); +} + +int xRandomness(sqlite3_vfs* vfs, int nByte, char* zOut) { + sqlite3_vfs* orig_vfs = static_cast<sqlite3_vfs*>(vfs->pAppData); + return orig_vfs->xRandomness(orig_vfs, nByte, zOut); +} + +int xSleep(sqlite3_vfs* vfs, int microseconds) { + sqlite3_vfs* orig_vfs = static_cast<sqlite3_vfs*>(vfs->pAppData); + return orig_vfs->xSleep(orig_vfs, microseconds); +} + +int xCurrentTime(sqlite3_vfs* vfs, double* prNow) { + sqlite3_vfs* orig_vfs = static_cast<sqlite3_vfs*>(vfs->pAppData); + return orig_vfs->xCurrentTime(orig_vfs, prNow); +} + +int xGetLastError(sqlite3_vfs* vfs, int nBuf, char* zBuf) { + sqlite3_vfs* orig_vfs = static_cast<sqlite3_vfs*>(vfs->pAppData); + return orig_vfs->xGetLastError(orig_vfs, nBuf, zBuf); +} + +int xCurrentTimeInt64(sqlite3_vfs* vfs, sqlite3_int64* piNow) { + sqlite3_vfs* orig_vfs = static_cast<sqlite3_vfs*>(vfs->pAppData); + return orig_vfs->xCurrentTimeInt64(orig_vfs, piNow); +} + +static int xSetSystemCall(sqlite3_vfs* vfs, const char* zName, + sqlite3_syscall_ptr pFunc) { + sqlite3_vfs* orig_vfs = static_cast<sqlite3_vfs*>(vfs->pAppData); + return orig_vfs->xSetSystemCall(orig_vfs, zName, pFunc); +} + +static sqlite3_syscall_ptr xGetSystemCall(sqlite3_vfs* vfs, const char* zName) { + sqlite3_vfs* orig_vfs = static_cast<sqlite3_vfs*>(vfs->pAppData); + return orig_vfs->xGetSystemCall(orig_vfs, zName); +} + +static const char* xNextSystemCall(sqlite3_vfs* vfs, const char* zName) { + sqlite3_vfs* orig_vfs = static_cast<sqlite3_vfs*>(vfs->pAppData); + return orig_vfs->xNextSystemCall(orig_vfs, zName); +} + +} // namespace + +namespace mozilla { +namespace storage { + +const char* GetTelemetryVFSName(bool exclusive) { + return exclusive ? "telemetry-vfs-excl" : "telemetry-vfs"; +} + +UniquePtr<sqlite3_vfs> ConstructTelemetryVFS(bool exclusive) { +#if defined(XP_WIN) +# define EXPECTED_VFS "win32" +# define EXPECTED_VFS_EXCL "win32" +#else +# define EXPECTED_VFS "unix" +# define EXPECTED_VFS_EXCL "unix-excl" +#endif + + bool expected_vfs; + sqlite3_vfs* vfs; + if (!exclusive) { + // Use the non-exclusive VFS. + vfs = sqlite3_vfs_find(nullptr); + expected_vfs = vfs->zName && !strcmp(vfs->zName, EXPECTED_VFS); + } else { + vfs = sqlite3_vfs_find(EXPECTED_VFS_EXCL); + expected_vfs = (vfs != nullptr); + } + if (!expected_vfs) { + return nullptr; + } + + auto tvfs = MakeUnique<::sqlite3_vfs>(); + memset(tvfs.get(), 0, sizeof(::sqlite3_vfs)); + // If the VFS version is higher than the last known one, you should update + // this VFS adding appropriate methods for any methods added in the version + // change. + tvfs->iVersion = vfs->iVersion; + MOZ_ASSERT(vfs->iVersion <= LAST_KNOWN_VFS_VERSION); + tvfs->szOsFile = + sizeof(telemetry_file) - sizeof(sqlite3_file) + vfs->szOsFile; + tvfs->mxPathname = vfs->mxPathname; + tvfs->zName = GetTelemetryVFSName(exclusive); + tvfs->pAppData = vfs; + tvfs->xOpen = xOpen; + tvfs->xDelete = xDelete; + tvfs->xAccess = xAccess; + tvfs->xFullPathname = xFullPathname; + tvfs->xDlOpen = xDlOpen; + tvfs->xDlError = xDlError; + tvfs->xDlSym = xDlSym; + tvfs->xDlClose = xDlClose; + tvfs->xRandomness = xRandomness; + tvfs->xSleep = xSleep; + tvfs->xCurrentTime = xCurrentTime; + tvfs->xGetLastError = xGetLastError; + if (tvfs->iVersion >= 2) { + // Methods added in version 2. + tvfs->xCurrentTimeInt64 = xCurrentTimeInt64; + } + if (tvfs->iVersion >= 3) { + // Methods added in version 3. + tvfs->xSetSystemCall = xSetSystemCall; + tvfs->xGetSystemCall = xGetSystemCall; + tvfs->xNextSystemCall = xNextSystemCall; + } + return tvfs; +} + +already_AddRefed<QuotaObject> GetQuotaObjectForFile(sqlite3_file* pFile) { + MOZ_ASSERT(pFile); + + telemetry_file* p = (telemetry_file*)pFile; + RefPtr<QuotaObject> result = p->quotaObject; + return result.forget(); +} + +} // namespace storage +} // namespace mozilla |