Implements a mechanism that limit the growth of the application cache

2 files changed, 15 insertions, 0 deletions

diff --git a/WebCore/platform/sql/SQLiteDatabase.cpp b/WebCore/platform/sql/SQLiteDatabase.cpp
index 702cf02..e16b04e 100644
--- a/WebCore/platform/sql/SQLiteDatabase.cpp
+++ b/WebCore/platform/sql/SQLiteDatabase.cpp
@@ -151,6 +151,18 @@ int SQLiteDatabase::pageSize()
     return m_pageSize;
 }
 
+int64_t SQLiteDatabase::freeSpaceSize()
+{
+    MutexLocker locker(m_authorizerLock);
+    enableAuthorizer(false);
+    // Note: freelist_count was added in SQLite 3.4.1.
+    SQLiteStatement statement(*this, "PRAGMA freelist_count");
+    int64_t size = statement.getColumnInt64(0) * pageSize();
+
+    enableAuthorizer(true);
+    return size;
+}
+
 void SQLiteDatabase::setSynchronous(SynchronousPragma sync)
 {
     executeCommand(String::format("PRAGMA synchronous = %i", sync));
diff --git a/WebCore/platform/sql/SQLiteDatabase.h b/WebCore/platform/sql/SQLiteDatabase.h
index 76700dc..d313435 100644
--- a/WebCore/platform/sql/SQLiteDatabase.h
+++ b/WebCore/platform/sql/SQLiteDatabase.h
@@ -83,6 +83,9 @@ public:
     int64_t maximumSize();
     void setMaximumSize(int64_t);
     
+    // Gets the number of unused bytes in the database file.
+    int64_t freeSpaceSize();
+
     // The SQLite SYNCHRONOUS pragma can be either FULL, NORMAL, or OFF
     // FULL - Any writing calls to the DB block until the data is actually on the disk surface
     // NORMAL - SQLite pauses at some critical moments when writing, but much less than FULL