commit 1b5c604d9d344537941b11b136348edfc39f236c
author halcanary <halcanary@google.com> Wed Feb 18 11:29:56 2015 -0800
committer Commit bot <commit-bot@chromium.org> Wed Feb 18 11:29:57 2015 -0800
tree 72110f65007d2e0af1cc525376488ed360b6a07d
parent 0babd3c61987428a5c532f65be9d98c7ac583e0d

PDF: Add (low-memory) SkPDFBitmap class

Also: Add SkDeflateWStream and associated unit tests.

SkPDFBitmap is a replacement for SkPDFImage.  As of now, it only
supports 8888 bitmaps (the most common case).

SkPDFBitmap takes very little extra memory (aside from refing the
bitmap's pixels), and its emitObject() does not cache any data.

The SkPDFBitmap::Create function will check the canon for duplicates.
This can reduce the size of the output PDF.

Motivation:  this gives another ~40% decrease in PDF memory overhead

TODO: Support other ColorTypes and scrap SkPDFImage.

BUG=skia:3030

Review URL: https://codereview.chromium.org/918813002

src/pdf/SkPDFCanon.cpp

diff --git a/src/pdf/SkPDFCanon.cpp b/src/pdf/SkPDFCanon.cpp
index 6b52018..268a53a8 100644
--- a/src/pdf/SkPDFCanon.cpp
+++ b/src/pdf/SkPDFCanon.cpp
@@ -6,6 +6,7 @@
  */
 
 #include "SkLazyPtr.h"
+#include "SkPDFBitmap.h"
 #include "SkPDFCanon.h"
 #include "SkPDFFont.h"
 #include "SkPDFGraphicState.h"
@@ -16,10 +17,12 @@
 SK_DECLARE_STATIC_MUTEX(gSkPDFCanonFontMutex);
 SK_DECLARE_STATIC_MUTEX(gSkPDFCanonShaderMutex);
 SK_DECLARE_STATIC_MUTEX(gSkPDFCanonPaintMutex);
+SK_DECLARE_STATIC_MUTEX(gSkPDFCanonBitmapMutex);
 
 SkBaseMutex& SkPDFCanon::GetFontMutex() { return gSkPDFCanonFontMutex; }
 SkBaseMutex& SkPDFCanon::GetShaderMutex() { return gSkPDFCanonShaderMutex; }
 SkBaseMutex& SkPDFCanon::GetPaintMutex() { return gSkPDFCanonPaintMutex; }
+SkBaseMutex& SkPDFCanon::GetBitmapMutex() { return gSkPDFCanonBitmapMutex; }
 
 SkPDFCanon::SkPDFCanon() {}
 
@@ -168,3 +171,20 @@
     assert_mutex_held(this, gSkPDFCanonPaintMutex);
     SkAssertResult(remove_item(&fGraphicStateRecords, pdfGraphicState));
 }
+
+////////////////////////////////////////////////////////////////////////////////
+
+SkPDFBitmap* SkPDFCanon::findBitmap(const SkBitmap& bm) const {
+    assert_mutex_held(this, gSkPDFCanonBitmapMutex);
+    return find_item(fBitmapRecords, bm);
+}
+
+void SkPDFCanon::addBitmap(SkPDFBitmap* pdfBitmap) {
+    assert_mutex_held(this, gSkPDFCanonBitmapMutex);
+    fBitmapRecords.push(assert_ptr(pdfBitmap));
+}
+
+void SkPDFCanon::removeBitmap(SkPDFBitmap* pdfBitmap) {
+    assert_mutex_held(this, gSkPDFCanonBitmapMutex);
+    SkAssertResult(remove_item(&fBitmapRecords, pdfBitmap));
+}