Bug 836039 - Reduce cache size per SQLite connection to 2MB

r=asuth
Brli · Feb 21, 2013 · 7e4bc03 · 7e4bc03
1 parent 47a89b1
commit 7e4bc03
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Showing 3 changed files with 8 additions and 32 deletions.
diff --git a/storage/src/mozStorageConnection.cpp b/storage/src/mozStorageConnection.cpp
@@ -43,12 +43,8 @@
 
 #define MIN_AVAILABLE_BYTES_PER_CHUNKED_GROWTH 524288000 // 500 MiB
 
-// Maximum size of the pages cache per connection.  If the default cache_size
-// value evaluates to a larger size, it will be reduced to save memory.
-#define MAX_CACHE_SIZE_BYTES 4194304 // 4 MiB
-
-// Default maximum number of pages to allow in the connection pages cache.
-#define DEFAULT_CACHE_SIZE_PAGES 2000
+// Maximum size of the pages cache per connection.
+#define MAX_CACHE_SIZE_KIBIBYTES 2048 // 2 MiB
 
 #ifdef PR_LOGGING
 PRLogModuleInfo* gStorageLog = nullptr;
@@ -576,26 +572,13 @@ Connection::initializeInternal(nsIFile* aDatabaseFile)
   nsresult rv = ExecuteSimpleSQL(pageSizeQuery);
   NS_ENSURE_SUCCESS(rv, rv);
 
-  // Get the current page_size, since it may differ from the specified value.
-  sqlite3_stmt *stmt;
-  NS_NAMED_LITERAL_CSTRING(pragma_page_size,
-                           MOZ_STORAGE_UNIQUIFY_QUERY_STR "PRAGMA page_size");
-  int srv = prepareStatement(pragma_page_size, &stmt);
-  if (srv == SQLITE_OK) {
-    if (SQLITE_ROW == stepStatement(stmt)) {
-      pageSize = ::sqlite3_column_int64(stmt, 0);
-    }
-    (void)::sqlite3_finalize(stmt);
-  }
-
   // Setting the cache_size forces the database open, verifying if it is valid
   // or corrupt.  So this is executed regardless it being actually needed.
   // The cache_size is calculated from the actual page_size, to save memory.
   nsAutoCString cacheSizeQuery(MOZ_STORAGE_UNIQUIFY_QUERY_STR
                                "PRAGMA cache_size = ");
-  cacheSizeQuery.AppendInt(std::min(DEFAULT_CACHE_SIZE_PAGES,
-                                  int32_t(MAX_CACHE_SIZE_BYTES / pageSize)));
-  srv = executeSql(cacheSizeQuery.get());
+  cacheSizeQuery.AppendInt(-MAX_CACHE_SIZE_KIBIBYTES);
+  int srv = executeSql(cacheSizeQuery.get());
   if (srv != SQLITE_OK) {
     ::sqlite3_close(mDBConn);
     mDBConn = nullptr;

diff --git a/storage/test/unit/test_cache_size.js b/storage/test/unit/test_cache_size.js
@@ -54,12 +54,7 @@ function new_file(name)
 
 function run_test()
 {
-  // This is copied from the logic in Connection::initialize().
-  function cacheSize(pageSize) {
-    const DEFAULT_CACHE_SIZE_PAGES = 2000;
-    const MAX_CACHE_SIZE_BYTES = 4 * 1024 * 1024;
-    return Math.min(DEFAULT_CACHE_SIZE_PAGES, MAX_CACHE_SIZE_BYTES / pageSize);
-  }
+  const kExpectedCacheSize = -2048; // 2MiB
 
   let pageSizes = [
     1024,
@@ -69,11 +64,9 @@ function run_test()
 
   for (let i = 0; i < pageSizes.length; i++) {
     let pageSize = pageSizes[i];
-    let expectedCacheSize = cacheSize(pageSize);
     check_size(getDatabase,
-               new_file("shared" + pageSize), pageSize, expectedCacheSize);
+               new_file("shared" + pageSize), pageSize, kExpectedCacheSize);
     check_size(getService().openUnsharedDatabase,
-               new_file("unshared" + pageSize), pageSize, expectedCacheSize);
+               new_file("unshared" + pageSize), pageSize, kExpectedCacheSize);
   }
 }
-
diff --git a/storage/test/unit/test_page_size_is_32k.js b/storage/test/unit/test_page_size_is_32k.js
@@ -5,7 +5,7 @@
 // This file tests that dbs are using 32k pagesize
 
 const kExpectedPageSize = 32768; // 32K
-const kExpectedCacheSize = 128; // (4MiB / 32KiB)
+const kExpectedCacheSize = -2048; // 2MiB
 
 function check_size(db)
 {