Avoid new for small arrays in SkBmpCodec

Use a buffer on the stack to avoid the cost of new/delete.

Change-Id: I5c9208ec283e8345c34553343925097926274978
Reviewed-on: https://skia-review.googlesource.com/18402
Reviewed-by: Matt Sarett <msarett@google.com>
Commit-Queue: Leon Scroggins <scroggo@google.com>

1 files changed, 13 insertions, 14 deletions

diff --git a/src/codec/SkBmpCodec.cpp b/src/codec/SkBmpCodec.cpp
index 3d3782b4f5..3158e992d2 100644
--- a/src/codec/SkBmpCodec.cpp
+++ b/src/codec/SkBmpCodec.cpp
@@ -151,15 +151,15 @@ bool SkBmpCodec::ReadHeader(SkStream* stream, bool inIco, SkCodec** codecOut) {
     // Bmps embedded in Icos skip the first Bmp header
     if (!inIco) {
         // Read the first header and the size of the second header
-        std::unique_ptr<uint8_t[]> hBuffer(new uint8_t[kBmpHeaderBytesPlusFour]);
-        if (stream->read(hBuffer.get(), kBmpHeaderBytesPlusFour) !=
+        uint8_t hBuffer[kBmpHeaderBytesPlusFour];
+        if (stream->read(hBuffer, kBmpHeaderBytesPlusFour) !=
                 kBmpHeaderBytesPlusFour) {
             SkCodecPrintf("Error: unable to read first bitmap header.\n");
             return false;
         }
 
-        totalBytes = get_int(hBuffer.get(), 2);
-        offset = get_int(hBuffer.get(), 10);
+        totalBytes = get_int(hBuffer, 2);
+        offset = get_int(hBuffer, 10);
         if (offset < kBmpHeaderBytes + kBmpOS2V1Bytes) {
             SkCodecPrintf("Error: invalid starting location for pixel data\n");
             return false;
@@ -168,7 +168,7 @@ bool SkBmpCodec::ReadHeader(SkStream* stream, bool inIco, SkCodec** codecOut) {
         // The size of the second (info) header in bytes
         // The size is the first field of the second header, so we have already
         // read the first four infoBytes.
-        infoBytes = get_int(hBuffer.get(), 14);
+        infoBytes = get_int(hBuffer, 14);
         if (infoBytes < kBmpOS2V1Bytes) {
             SkCodecPrintf("Error: invalid second header size.\n");
             return false;
@@ -185,12 +185,12 @@ bool SkBmpCodec::ReadHeader(SkStream* stream, bool inIco, SkCodec** codecOut) {
         offset = 0;
 
         // Read the size of the second header
-        std::unique_ptr<uint8_t[]> hBuffer(new uint8_t[4]);
-        if (stream->read(hBuffer.get(), 4) != 4) {
+        uint8_t hBuffer[4];
+        if (stream->read(hBuffer, 4) != 4) {
             SkCodecPrintf("Error: unable to read size of second bitmap header.\n");
             return false;
         }
-        infoBytes = get_int(hBuffer.get(), 0);
+        infoBytes = get_int(hBuffer, 0);
         if (infoBytes < kBmpOS2V1Bytes) {
             SkCodecPrintf("Error: invalid second header size.\n");
             return false;
@@ -332,16 +332,15 @@ bool SkBmpCodec::ReadHeader(SkStream* stream, bool inIco, SkCodec** codecOut) {
             switch (headerType) {
                 case kInfoV1_BmpHeaderType: {
                     // The V1 header stores the bit masks after the header
-                    std::unique_ptr<uint8_t[]> mBuffer(new uint8_t[kBmpMaskBytes]);
-                    if (stream->read(mBuffer.get(), kBmpMaskBytes) !=
-                            kBmpMaskBytes) {
+                    uint8_t buffer[kBmpMaskBytes];
+                    if (stream->read(buffer, kBmpMaskBytes) != kBmpMaskBytes) {
                         SkCodecPrintf("Error: unable to read bit inputMasks.\n");
                         return false;
                     }
                     maskBytes = kBmpMaskBytes;
-                    inputMasks.red = get_int(mBuffer.get(), 0);
-                    inputMasks.green = get_int(mBuffer.get(), 4);
-                    inputMasks.blue = get_int(mBuffer.get(), 8);
+                    inputMasks.red = get_int(buffer, 0);
+                    inputMasks.green = get_int(buffer, 4);
+                    inputMasks.blue = get_int(buffer, 8);
                     break;
                 }
                 case kInfoV2_BmpHeaderType: