Adding size parameter to read array functions

src/core/SkOrderedReadBuffer.cpp

Index: src/core/SkOrderedReadBuffer.cpp
diff --git a/src/core/SkOrderedReadBuffer.cpp b/src/core/SkOrderedReadBuffer.cpp
index d9aa8bd1d751d35c722bb05d79ddd291d0225461..31841182b9c47edbce0e0f85b1b9bef466620fe8 100644
--- a/src/core/SkOrderedReadBuffer.cpp
+++ b/src/core/SkOrderedReadBuffer.cpp
@@ -137,38 +137,37 @@ void SkOrderedReadBuffer::readPath(SkPath* path) {
     fReader.readPath(path);
 }
 
-uint32_t SkOrderedReadBuffer::readByteArray(void* value) {
-    const uint32_t length = fReader.readU32();
-    memcpy(value, fReader.skip(SkAlign4(length)), length);
-    return length;
+bool SkOrderedReadBuffer::readArray(void* value, size_t size, size_t elementSize) {
+    const size_t count = this->getArrayCount();
+    if (count == size) {

[Stephen White, 2013/10/31 15:19:28]

Nit: prefer the early-out to be the error case rather than the valid one.

+        (void)fReader.skip(sizeof(uint32_t)); // Skip array count
+        const size_t byteLength = count * elementSize;

[Stephen White, 2013/10/31 15:19:28]

Should we be checking for overflow here? At worst, I suppose we'll end up
reading fewer bytes, so I don't think there's a danger of buffer overflow, but I
could be wrong (there would probably be overflow at the malloc in the callsite
too).

+        memcpy(value, fReader.skip(SkAlign4(byteLength)), byteLength);
+        return true;
+    }
+    SkASSERT(false);
+    fReader.skip(fReader.available());
+    return false;
+}
+
+bool SkOrderedReadBuffer::readByteArray(void* value, size_t size) {
+    return readArray(static_cast<unsigned char*>(value), size, sizeof(unsigned char));
 }
 
-uint32_t SkOrderedReadBuffer::readColorArray(SkColor* colors) {
-    const uint32_t count = fReader.readU32();
-    const uint32_t byteLength = count * sizeof(SkColor);
-    memcpy(colors, fReader.skip(SkAlign4(byteLength)), byteLength);
-    return count;
+bool SkOrderedReadBuffer::readColorArray(SkColor* colors, size_t size) {
+    return readArray(colors, size, sizeof(SkColor));
 }
 
-uint32_t SkOrderedReadBuffer::readIntArray(int32_t* values) {
-    const uint32_t count = fReader.readU32();
-    const uint32_t byteLength = count * sizeof(int32_t);
-    memcpy(values, fReader.skip(SkAlign4(byteLength)), byteLength);
-    return count;
+bool SkOrderedReadBuffer::readIntArray(int32_t* values, size_t size) {
+    return readArray(values, size, sizeof(int32_t));
 }
 
-uint32_t SkOrderedReadBuffer::readPointArray(SkPoint* points) {
-    const uint32_t count = fReader.readU32();
-    const uint32_t byteLength = count * sizeof(SkPoint);
-    memcpy(points, fReader.skip(SkAlign4(byteLength)), byteLength);
-    return count;
+bool SkOrderedReadBuffer::readPointArray(SkPoint* points, size_t size) {
+    return readArray(points, size, sizeof(SkPoint));
 }
 
-uint32_t SkOrderedReadBuffer::readScalarArray(SkScalar* values) {
-    const uint32_t count = fReader.readU32();
-    const uint32_t byteLength = count * sizeof(SkScalar);
-    memcpy(values, fReader.skip(SkAlign4(byteLength)), byteLength);
-    return count;
+bool SkOrderedReadBuffer::readScalarArray(SkScalar* values, size_t size) {
+    return readArray(values, size, sizeof(SkScalar));
 }
 
 uint32_t SkOrderedReadBuffer::getArrayCount() {