Have peek32 return uint32_t& to make it harder to look at more than 4 bytes.

include/core/SkWriter32.h

 
 /*
  * Copyright 2008 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #ifndef SkWriter32_DEFINED
@@ skipping 61 matching lines @@
         if (fInternal.isEmpty() && this->externalCount() + count <= fExternalLimit) {
             p = fExternal + fCount;
         } else {
             p = fInternal.append(count);
         }
 
         fCount += count;
         return p;
     }
 
-    // return the address of the 4byte int at the specified offset (which must
-    // be a multiple of 4. This does not allocate any new space, so the returned
-    // address is only valid for 1 int.
-    uint32_t* peek32(size_t offset) {
-        SkASSERT(SkAlign4(offset) == offset);
-        const int count = SkToInt(offset/4);
-        SkASSERT(count < fCount);
-
-        if (count < this->externalCount()) {
-            return fExternal + count;
-        }
-        return &fInternal[count - this->externalCount()];
-    }
+    // Read or write 4 bytes at offset, which must be a multiple of 4 <= size().
+    uint32_t read32At(size_t offset) { return this->atOffset(offset); }
+    void write32At(size_t offset, uint32_t val) { this->atOffset(offset) = val; }
 
     bool writeBool(bool value) {
         this->write32(value);
         return value;
     }
 
     void writeInt(int32_t value) {
         this->write32(value);
     }
 
@@ skipping 103 matching lines @@
 
     /**
      *  Computes the size (aligned to multiple of 4) need to write the string
      *  in a call to writeString(). If the length is not specified, it will be
      *  computed by calling strlen().
      */
     static size_t WriteStringSize(const char* str, size_t len = (size_t)-1);
 
     /**
      *  Move the cursor back to offset bytes from the beginning.
-     *  This has the same restrictions as peek32: offset must be <= size() and
-     *  offset must be a multiple of 4.
+     *  offset must be a multiple of 4 no greater than size().
      */
     void rewindToOffset(size_t offset) {
         SkASSERT(SkAlign4(offset) == offset);
         const int count = SkToInt(offset/4);
         if (count < this->externalCount()) {
             fInternal.setCount(0);
         } else {
             fInternal.setCount(count - this->externalCount());
         }
         fCount = count;
@@ skipping 12 matching lines @@
             && stream->write(fInternal.begin(), fInternal.bytes());
     }
 
     // read from the stream, and write up to length bytes. Return the actual
     // number of bytes written.
     size_t readFromStream(SkStream* stream, size_t length) {
         return stream->read(this->reservePad(length), length);
     }
 
 private:
+    uint32_t& atOffset(size_t offset) {
+        SkASSERT(SkAlign4(offset) == offset);
+        const int count = SkToInt(offset/4);
+        SkASSERT(count < fCount);
+
+        if (count < this->externalCount()) {
+            return fExternal[count];
+        }
+        return fInternal[count - this->externalCount()];
+    }
+
+
     // Number of uint32_t written into fExternal.  <= fExternalLimit.
     int externalCount() const { return fCount - fInternal.count(); }
 
     int fCount;                     // Total number of uint32_t written.
     int fExternalLimit;             // Number of uint32_t we can write to fExternal.
     uint32_t* fExternal;            // Unmanaged memory block.
     SkTDArray<uint32_t> fInternal;  // Managed memory block.
 };
 
 /**
  *  Helper class to allocated SIZE bytes as part of the writer, and to provide
  *  that storage to the constructor as its initial storage buffer.
  *
  *  This wrapper ensures proper alignment rules are met for the storage.
  */
 template <size_t SIZE> class SkSWriter32 : public SkWriter32 {
 public:
     SkSWriter32() : SkWriter32(fData.fStorage, SIZE) {}
 
 private:
     union {
         void*   fPtrAlignment;
         double  fDoubleAlignment;
         char    fStorage[SIZE];
     } fData;
 };
 
 #endif