Remove config setters from sql/database.h
Most of the setters for configuration options for a SQLite database only
worked before the database was opened and were no-ops otherwise. This
led to confusing semantics and needing to support unnatural behaviour in
other parts of sql/ code.
This change removes the setters for the database config now encapsulated
in the DatabaseOptions struct. This struct is only set once as part of a
new constructor.
All feature code has already been migrated to use the new constructor
instead of the setter methods.
Bug: 1126968
Change-Id: I13474fbb87c7f2da386e83fb8d1fe3d8c44ab963
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2627941
Commit-Queue: Shubham Aggarwal <[email protected]>
Reviewed-by: Victor Costan <[email protected]>
Cr-Commit-Position: refs/heads/master@{#848097}
diff --git a/sql/database.h b/sql/database.h
index b4eeb9b..35601a48 100644
--- a/sql/database.h
+++ b/sql/database.h
@@ -56,6 +56,19 @@
// If true, the database can only be opened by one process at a time.
//
+ // SQLite supports a locking protocol that allows multiple processes to safely
+ // operate on the same database at the same time. The locking protocol is used
+ // on every transaction, and comes with a small performance penalty.
+ //
+ // Setting this to true causes the locking protocol to be used once, when the
+ // database is opened. No other process will be able to access the database at
+ // the same time.
+ //
+ // More details at https://www.sqlite.org/pragma.html#pragma_locking_mode
+ //
+ // SQLite's locking protocol is summarized at
+ // https://www.sqlite.org/c3ref/io_methods.html
+ //
// Exclusive mode is strongly recommended. It reduces the I/O cost of setting
// up a transaction. It also removes the need of handling transaction failures
// due to lock contention.
@@ -67,6 +80,13 @@
// Chrome features yet. In particular, our custom database recovery code does
// not support the WAL log file.
//
+ // WAL mode is currently not fully supported on FuchsiaOS. It will only be
+ // turned on if the database is also using exclusive locking mode.
+ // (https://crbug.com/1082059)
+ //
+ // Note: Changing page size is not supported when in WAL mode. So running
+ // 'PRAGMA page_size = <new-size>' will result in no-ops.
+ //
// More details at https://www.sqlite.org/wal.html
bool wal_mode =
base::FeatureList::IsEnabled(sql::features::kEnableWALModeByDefault);
@@ -76,6 +96,8 @@
// Larger page sizes result in shallower B-trees, because they allow an inner
// page to hold more keys. On the flip side, larger page sizes may result in
// more I/O when making small changes to existing records.
+ //
+ // Must be a power of two between 512 and 65536 inclusive.
int page_size = kDefaultPageSize;
// The size of in-memory cache, in pages.
@@ -116,70 +138,12 @@
// Pre-init configuration ----------------------------------------------------
- // Sets the page size that will be used when creating a new database. This
- // must be called before Init(), and will only have an effect on new
- // databases.
- //
- // The page size must be a power of two between 512 and 65536 inclusive.
- void set_page_size(int page_size) {
- DCHECK_GE(page_size, 512);
- DCHECK_LE(page_size, 65536);
- DCHECK(!(page_size & (page_size - 1)))
- << "page_size must be a power of two";
-
- options_.page_size = page_size;
- }
-
// The page size that will be used when creating a new database.
int page_size() const { return options_.page_size; }
- // Sets the number of pages that will be cached in memory by sqlite. The
- // total cache size in bytes will be page_size * cache_size. This must be
- // called before Open() to have an effect.
- void set_cache_size(int cache_size) {
- DCHECK_GE(cache_size, 0);
-
- options_.cache_size = cache_size;
- }
-
// Returns whether a database will be opened in WAL mode.
bool UseWALMode() const;
- // Enables/disables WAL mode (https://www.sqlite.org/wal.html) when
- // opening a new database.
- //
- // WAL mode is currently not fully supported on FuchsiaOS. It will only be
- // turned on if the database is also using exclusive locking mode.
- // (https://crbug.com/1082059)
- //
- // Note: Changing page size is not supported when in WAL mode. So running
- // 'PRAGMA page_size = <new-size>' or using set_page_size will result in
- // no-ops.
- //
- // This must be called before Open() to have an effect.
- void want_wal_mode(bool enabled) { options_.wal_mode = enabled; }
-
- // Makes database accessible by only one process at a time.
- //
- // TODO(https://crbug.com/1120969): This should be the default mode. The
- // "NORMAL" mode should be opt-in.
- //
- // SQLite supports a locking protocol that allows multiple processes to safely
- // operate on the same database at the same time. The locking protocol is used
- // on every transaction, and comes with a small performance penalty.
- //
- // Calling this method causes the locking protocol to be used once, when the
- // database is opened. No other process will be able to access the database at
- // the same time.
- //
- // This method must be called before Open() to have an effect.
- //
- // More details at https://www.sqlite.org/pragma.html#pragma_locking_mode
- //
- // SQLite's locking protocol is summarized at
- // https://www.sqlite.org/c3ref/io_methods.html
- void set_exclusive_locking() { options_.exclusive_locking = true; }
-
// Call to use alternative status-tracking for mmap. Usually this is tracked
// in the meta table, but some databases have no meta table.
// TODO(shess): Maybe just have all databases use the alt option?
