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author | shess <shess@chromium.org> | 2015-11-12 18:24:31 -0800 |
---|---|---|
committer | Commit bot <commit-bot@chromium.org> | 2015-11-13 02:25:28 +0000 |
commit | d90aeea87619c019f8b4be171b65476748868ece (patch) | |
tree | 99a05a0c61b68d2fe2f2119ae80ab698dac35bdd /sql/connection.h | |
parent | cc5ac2aca0c601c848b6dc356f949ff3ec0a6194 (diff) | |
download | chromium_src-d90aeea87619c019f8b4be171b65476748868ece.zip chromium_src-d90aeea87619c019f8b4be171b65476748868ece.tar.gz chromium_src-d90aeea87619c019f8b4be171b65476748868ece.tar.bz2 |
[sql] Validate database files before enabling memory-mapping.
With regular I/O, filesystem corruption would cause SQLite to return
SQLITE_IOERR codes. With memory-mapping, filesystem errors can cause a
crash when accessed. There are databases with filesystem corruption,
this CL only enables memory-mapped I/O for parts of the database which
have been successfully read at some point using regular I/O.
[Relands https://codereview.chromium.org/1426743006 which was reverted at
https://codereview.chromium.org/1432953002 . CL is identical, fix to
sql::Connection was landed at https://codereview.chromium.org/1426743006 .]
BUG=537742
TBR=rmcilroy@chromium.org, isherman+reviewer@chromium.org
Review URL: https://codereview.chromium.org/1442753004
Cr-Commit-Position: refs/heads/master@{#359478}
Diffstat (limited to 'sql/connection.h')
-rw-r--r-- | sql/connection.h | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/sql/connection.h b/sql/connection.h index 5b219db..18b2cb7 100644 --- a/sql/connection.h +++ b/sql/connection.h @@ -204,6 +204,19 @@ class SQL_EXPORT Connection : public base::trace_event::MemoryDumpProvider { EVENT_COMMIT, EVENT_ROLLBACK, + // Track success and failure in GetAppropriateMmapSize(). + // GetAppropriateMmapSize() should record at most one of these per run. The + // case of mapping everything is not recorded. + EVENT_MMAP_META_MISSING, // No meta table present. + EVENT_MMAP_META_FAILURE_READ, // Failed reading meta table. + EVENT_MMAP_META_FAILURE_UPDATE, // Failed updating meta table. + EVENT_MMAP_VFS_FAILURE, // Failed to access VFS. + EVENT_MMAP_FAILED, // Failure from past run. + EVENT_MMAP_FAILED_NEW, // Read error in this run. + EVENT_MMAP_SUCCESS_NEW, // Read to EOF in this run. + EVENT_MMAP_SUCCESS_PARTIAL, // Read but did not reach EOF. + EVENT_MMAP_SUCCESS_NO_PROGRESS, // Read quota exhausted. + // Leave this at the end. // TODO(shess): |EVENT_MAX| causes compile fail on Windows. EVENT_MAX_VALUE @@ -693,6 +706,16 @@ class SQL_EXPORT Connection : public base::trace_event::MemoryDumpProvider { // Helper to collect diagnostic info for errors. std::string CollectErrorInfo(int error, Statement* stmt) const; + // Calculates a value appropriate to pass to "PRAGMA mmap_size = ". So errors + // can make it unsafe to map a file, so the file is read using regular I/O, + // with any errors causing 0 (don't map anything) to be returned. If the + // entire file is read without error, a large value is returned which will + // allow the entire file to be mapped in most cases. + // + // Results are recorded in the database's meta table for future reference, so + // the file should only be read through once. + size_t GetAppropriateMmapSize(); + // The actual sqlite database. Will be NULL before Init has been called or if // Init resulted in an error. sqlite3* db_; |