Add deflate support to SkPDFStream.

Review URL: http://codereview.appspot.com/3326043

git-svn-id: http://skia.googlecode.com/svn/trunk@627 2bbb7eff-a529-9590-31e7-b0007b416f81

1 files changed, 129 insertions, 0 deletions

diff --git a/src/core/SkFlate.cpp b/src/core/SkFlate.cpp
new file mode 100644
index 0000000000..a9adece75e
--- /dev/null
+++ b/src/core/SkFlate.cpp
@@ -0,0 +1,129 @@
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "SkFlate.h"
+#include "SkStream.h"
+
+#ifndef SK_ZLIB_INCLUDE
+bool SkFlate::HaveFlate() { return false; }
+bool SkFlate::Deflate(SkStream*, SkDynamicMemoryWStream*) { return false; }
+bool SkFlate::Inflate(SkStream*, SkDynamicMemoryWStream*) { return false; }
+#else
+
+// static
+const size_t SkFlate::kBufferSize = 1024;
+
+// static
+bool SkFlate::HaveFlate() {
+    return true;
+}
+
+namespace {
+
+#include SK_ZLIB_INCLUDE
+
+bool doFlate(bool compress, const size_t kBufferSize, SkStream* src,
+             SkDynamicMemoryWStream* dst) {
+    uint8_t inputBuffer[kBufferSize];
+    uint8_t outputBuffer[kBufferSize];
+    z_stream flateData;
+    flateData.zalloc = NULL;
+    flateData.zfree = NULL;
+    flateData.next_in = NULL;
+    flateData.avail_in = 0;
+    flateData.next_out = outputBuffer;
+    flateData.avail_out = kBufferSize;
+    int rc;
+    if (compress)
+        rc = deflateInit(&flateData, Z_DEFAULT_COMPRESSION);
+    else
+        rc = inflateInit(&flateData);
+    if (rc != Z_OK)
+        return false;
+
+    uint8_t* input = (uint8_t*)src->getMemoryBase();
+    size_t inputLength = src->getLength();
+    if (input == NULL || inputLength < 0) {
+        input = NULL;
+        flateData.next_in = inputBuffer;
+        flateData.avail_in = 0;
+    } else {
+        flateData.next_in = input;
+        flateData.avail_in = inputLength;
+    }
+
+    rc = Z_OK;
+    while (true) {
+        if (flateData.avail_out < kBufferSize) {
+            if (!dst->write(outputBuffer, kBufferSize - flateData.avail_out)) {
+                rc = Z_BUF_ERROR;
+                break;
+            }
+            flateData.next_out = outputBuffer;
+            flateData.avail_out = kBufferSize;
+        }
+        if (flateData.avail_in == 0) {
+            if (input != NULL)
+                break;
+            size_t read = src->read(&inputBuffer, kBufferSize);
+            if (read == 0)
+                break;
+            flateData.next_in = inputBuffer;
+            flateData.avail_in = read;
+        }
+        if (compress)
+            rc = deflate(&flateData, Z_NO_FLUSH);
+        else
+            rc = inflate(&flateData, Z_NO_FLUSH);
+        if (rc != Z_OK)
+            break;
+    }
+    while (rc == Z_OK) {
+        if (compress)
+            rc = deflate(&flateData, Z_FINISH);
+        else
+            rc = inflate(&flateData, Z_FINISH);
+        if (flateData.avail_out > 0) {
+            if (!dst->write(outputBuffer, kBufferSize - flateData.avail_out))
+                return false;
+            flateData.next_out = outputBuffer;
+            flateData.avail_out = kBufferSize;
+        }
+    }
+
+    if (compress)
+        deflateEnd(&flateData);
+    else
+        inflateEnd(&flateData);
+    if (rc == Z_STREAM_END)
+        return true;
+    return false;
+}
+
+}
+
+// static
+bool SkFlate::Deflate(SkStream* src, SkDynamicMemoryWStream* dst) {
+    return doFlate(true, kBufferSize, src, dst);
+}
+
+// static
+bool SkFlate::Inflate(SkStream* src, SkDynamicMemoryWStream* dst) {
+    return doFlate(false, kBufferSize, src, dst);
+}
+
+#endif
+