third_party/sqlite/sqlite_common_configuration_flags.gni

# Compile-time options passed to SQLite when compiling and building
# the Chromium amalgamations.
sqlite_common_configuration_flags = [
  # Chrome does not enable fts4, disable extra code.
  "SQLITE_DISABLE_FTS4_DEFERRED",
  "SQLITE_ENABLE_ICU",

  # Defaults the secure_delete pragma to 1.
  #
  # This causes SQLite to overwrite all deleted information with zeroes,
  # trading additional I/O for better privacy guarantees.
  "SQLITE_SECURE_DELETE",

  # TODO(pwnall): SQLite adds mutexes to protect structures which cross
  # threads. In theory Chrome should be able to turn this to "2" which
  # should give a slight speed boost. "2" is safe as long as a single
  # connection is not used by more than one thread at a time.
  "SQLITE_THREADSAFE=1",

  # SQLite can spawn threads to sort in parallel if configured
  # appropriately.  Chrome doesn't configure SQLite for that, and would
  # prefer to control distribution to worker threads.
  "SQLITE_MAX_WORKER_THREADS=0",

  # Allow 256MB mmap footprint per connection.  Should not be too open-ended
  # as that could cause memory fragmentation.  50MB encompasses the 99th
  # percentile of Chrome databases in the wild.
  # TODO(pwnall): A 64-bit-specific value could be 1G or more.
  # TODO(pwnall): Figure out if exceeding this is costly.
  "SQLITE_MAX_MMAP_SIZE=268435456",

  # The default POSIX permissions for a newly created SQLite database.
  #
  # If unspecified, this defaults to 0644. All the data stored by Chrome is
  # private, so our databases use stricter settings.
  "SQLITE_DEFAULT_FILE_PERMISSIONS=0600",

  # Databases are opened in EXCLUSIVE mode by default.
  #
  # NORMAL mode, where a database can be used by multiple processes
  # simultaneously, can be enabled by executing "PRAGMA locking_mode=0".
  #
  # https://www.sqlite.org/compile.html#default_locking_mode
  # https://www.sqlite.org/pragma.html#pragma_locking_mode
  "SQLITE_DEFAULT_LOCKING_MODE=1",

  # Needed by the SQL MemoryDumpProvider.
  #
  # Setting this to 1 is needed to collect the information reported by
  # sqlite3_status64(SQLITE_STATUS_MEMORY_USED). Without this setting, the API
  # still exists, but does not work as promised.
  "SQLITE_DEFAULT_MEMSTATUS=1",

  # Must match sql::Database::kDefaultPageSize.
  "SQLITE_DEFAULT_PAGE_SIZE=4096",

  # By default SQLite pre-allocates 100 pages of pcache data, which will not
  # be released until the handle is closed.  This is contrary to Chrome's
  # memory-usage goals.
  "SQLITE_DEFAULT_PCACHE_INITSZ=0",

  # The flags below are recommended in the SQLite documentation.
  "SQLITE_LIKE_DOESNT_MATCH_BLOBS",
  "SQLITE_OMIT_DEPRECATED",
  "SQLITE_OMIT_PROGRESS_CALLBACK",
  "SQLITE_OMIT_SHARED_CACHE",
  "SQLITE_USE_ALLOCA",

  # Chrome does not use sqlite3_column_decltype().
  "SQLITE_OMIT_DECLTYPE",

  # Chrome does not use SQLite's JSON support.
  "SQLITE_OMIT_JSON",

  # Chrome does not use sqlite3_{enable_}load_extension().
  # Asides from giving us fairly minor code savings, this option disables code
  # that breaks our method for renaming SQLite's exported symbols. Last,
  # there's a tiny security benefit to knowing that WebSQL can't possibly
  # reach extension loading code.
  "SQLITE_OMIT_LOAD_EXTENSION",

  # Uses isnan() in the C99 standard library.
  "SQLITE_HAVE_ISNAN",

  # Chrome uses SQLite's built-in corruption recovery module.
  # See https://www.sqlite.org/recovery.html
  #
  # Use of this module requires compiling a separate "sqlite3r.c" target, which
  # generates "sqlite3r.c" and "sqlite3r.h", versions of the amalgamation files
  # that include the recover extension. We then map this back to "sqlite3.h"
  # when generating amalgamations to hide this detail from the rest of the
  # platform. If this changes, or if we ever remove this flag, we would need to
  # update the mapping in scripts/generate_amalgamation.py.
  "SQLITE_HAVE_SQLITE3R",

  # See https://www.sqlite.org/dbpage.html
  #
  # This extension is required to use the built-in corruption recovery module
  # (see https://sqlite.org/src/info/c1f2a1d55c180fb5), which needs read access
  # to the sqlite_dbpage table. This table should not be accessed anywhere else
  # in Chrome or by untrusted third-parties (i.e. WebSQL).
  "SQLITE_ENABLE_DBPAGE_VTAB",
]