Checking structure sizes before reading them from memory to avoid overflowing the buffer's stream.

tests/MatrixTest.cpp

 
 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #include "Test.h"
 #include "SkMath.h"
 #include "SkMatrix.h"
 #include "SkMatrixUtils.h"
 #include "SkRandom.h"
+#include "SkReader32.h"
+#include "SkWriter32.h"
 
 static bool nearly_equal_scalar(SkScalar a, SkScalar b) {
     // Note that we get more compounded error for multiple operations when
     // SK_SCALAR_IS_FIXED.
 #ifdef SK_SCALAR_IS_FLOAT
     const SkScalar tolerance = SK_Scalar1 / 200000;
 #else
     const SkScalar tolerance = SK_Scalar1 / 1024;
 #endif
 
@@ skipping 82 matching lines @@
 
     dst = src;
     dst.fRight = src.fRight * 2;
     matrix.setRectToRect(src, dst, SkMatrix::kFill_ScaleToFit);
     REPORTER_ASSERT(reporter, SkMatrix::kScale_Mask == matrix.getType());
     REPORTER_ASSERT(reporter, matrix.rectStaysRect());
 }
 
 static void test_flatten(skiatest::Reporter* reporter, const SkMatrix& m) {
     // add 100 in case we have a bug, I don't want to kill my stack in the test
-    char buffer[SkMatrix::kMaxFlattenSize + 100];
-    uint32_t size1 = m.writeToMemory(NULL);
-    uint32_t size2 = m.writeToMemory(buffer);
+    static const uint32_t kBufferSize = SkWriter32::MaxWriteMatrixSize() + 100;
+    char buffer[kBufferSize];
+    SkWriter32 writer(SkWriter32::MaxWriteMatrixSize(), buffer, kBufferSize);
+    uint32_t size1 = writer.writeMatrixSize(m);
+    writer.writeMatrix(m);
+    uint32_t size2 = writer.bytesWritten();
     REPORTER_ASSERT(reporter, size1 == size2);
-    REPORTER_ASSERT(reporter, size1 <= SkMatrix::kMaxFlattenSize);
+    REPORTER_ASSERT(reporter, size1 <= SkWriter32::MaxWriteMatrixSize());
 
     SkMatrix m2;
-    uint32_t size3 = m2.readFromMemory(buffer);
+    SkReader32 reader(buffer, kBufferSize);
+    reader.readMatrix(&m2);
+    uint32_t size3 = reader.offset();
     REPORTER_ASSERT(reporter, size1 == size3);
     REPORTER_ASSERT(reporter, are_equal(reporter, m, m2));
 
-    char buffer2[SkMatrix::kMaxFlattenSize + 100];
-    size3 = m2.writeToMemory(buffer2);
+    char buffer2[kBufferSize];
+    SkWriter32 writer2(SkWriter32::MaxWriteMatrixSize(), buffer2, kBufferSize);
+    writer2.writeMatrix(m2);
+    size3 = writer2.bytesWritten();
     REPORTER_ASSERT(reporter, size1 == size3);
     REPORTER_ASSERT(reporter, memcmp(buffer, buffer2, size1) == 0);
 }
 
 static void test_matrix_max_stretch(skiatest::Reporter* reporter) {
     SkMatrix identity;
     identity.reset();
     REPORTER_ASSERT(reporter, SK_Scalar1 == identity.getMaxStretch());
 
     SkMatrix scale;
@@ skipping 660 matching lines @@
 
     test_matrix_max_stretch(reporter);
     test_matrix_is_similarity(reporter);
     test_matrix_recttorect(reporter);
     test_matrix_decomposition(reporter);
     test_matrix_homogeneous(reporter);
 }
 
 #include "TestClassDef.h"
 DEFINE_TESTCLASS("Matrix", MatrixTestClass, TestMatrix)