Changeset 48752 in webkit

Timestamp:

Sep 25, 2009 1:54:55 AM (15 years ago)

Author:

Simon Hausmann

Message:

​https://bugs.webkit.org/show_bug.cgi?id=28876
[Qt] reduce peak memory consumption of text decoding.

Patch by Yongjun Zhang <​yongjun.zhang@nokia.com> on 2009-09-25
Reviewed by Ariya Hidayat.

Chop large input buffer into small buffers to reduce peak memory
during decoding.

• platform/text/qt/TextCodecQt.cpp:

(WebCore::TextCodecQt::decode):

Location:

trunk/WebCore

Files:

• ChangeLog (modified) (1 diff)
• platform/text/qt/TextCodecQt.cpp (modified) (1 diff)

trunk/WebCore/ChangeLog

@@ +1 @@
+2009-09-25  Yongjun Zhang  <yongjun.zhang@nokia.com>
+
+        Reviewed by Ariya Hidayat.
+
+        https://bugs.webkit.org/show_bug.cgi?id=28876
+        [Qt] reduce peak memory consumption of text decoding.
+
+        Chop large input buffer into small buffers to reduce peak memory
+        during decoding.
+
+        * platform/text/qt/TextCodecQt.cpp:
+        (WebCore::TextCodecQt::decode):
+
 2009-09-24  Jon Honeycutt  <jhoneycutt@apple.com>
 

trunk/WebCore/platform/text/qt/TextCodecQt.cpp

@@ -95 +95 @@
 String TextCodecQt::decode(const char* bytes, size_t length, bool flush, bool /*stopOnError*/, bool& sawError)
 {
-    QString unicode = m_codec->toUnicode(bytes, length, &m_state);
+    // We chop input buffer to smaller buffers to avoid excessive memory consumption
+    // when the input buffer is big.  This helps reduce peak memory consumption in
+    // mobile devices where system RAM is limited.
+#if PLATFORM(SYMBIAN)
+    static const int MaxInputChunkSize = 32 * 1024;
+#else
+    static const int MaxInputChunkSize = 1024 * 1024;
+#endif
+    const char* buf = bytes;
+    const char* end = buf + length;
+    String unicode;
+
+    while (buf < end) {
+        int size = end - buf;
+        size = qMin(size, MaxInputChunkSize);
+        QString decoded = m_codec->toUnicode(buf, size, &m_state);
+        unicode.append(decoded);
+        buf += size;
+    }
+
     sawError = m_state.invalidChars != 0;