Initial import of Widevine Common Encryption DRM engine

Builds libwvmdrmengine.so, which is loaded by the new
MediaDrm APIs to support playback of Widevine/CENC
protected content.

Change-Id: I6f57dd37083dfd96c402cb9dd137c7d74edc8f1c

libwvdrmengine/cdm/core/include/buffer_reader.h

@@ -0,0 +1,68 @@
+// Copyright 2012 Google Inc. All Rights Reserved.
+
+#ifndef CDM_BASE_BUFFER_READER_H_
+#define CDM_BASE_BUFFER_READER_H_
+
+#include <stdint.h>
+#include <string>
+#include <vector>
+
+#include "wv_cdm_types.h"
+
+namespace wvcdm {
+
+// Annotate a function indicating the caller must examine the return value.
+// Use like:
+//   int foo() WARN_UNUSED_RESULT;
+// To explicitly ignore a result, see |ignore_result()| in <base/basictypes.h>.
+#if defined(COMPILER_GCC)
+#define WARN_UNUSED_RESULT __attribute__((warn_unused_result))
+#else
+#define WARN_UNUSED_RESULT
+#endif
+
+class BufferReader {
+ public:
+  BufferReader(const uint8_t* buf, size_t size)
+    : buf_(buf), size_(size), pos_(0) {}
+
+  bool HasBytes(int count) { return (pos() + count <= size()); }
+
+  // Read a value from the stream, performing endian correction,
+  // and advance the stream pointer.
+  bool Read1(uint8_t* v)  WARN_UNUSED_RESULT;
+  bool Read2(uint16_t* v) WARN_UNUSED_RESULT;
+  bool Read2s(int16_t* v) WARN_UNUSED_RESULT;
+  bool Read4(uint32_t* v) WARN_UNUSED_RESULT;
+  bool Read4s(int32_t* v) WARN_UNUSED_RESULT;
+  bool Read8(uint64_t* v) WARN_UNUSED_RESULT;
+  bool Read8s(int64_t* v) WARN_UNUSED_RESULT;
+
+  bool ReadString(std::string* str, int count) WARN_UNUSED_RESULT;
+  bool ReadVec(std::vector<uint8_t>* t, int count) WARN_UNUSED_RESULT;
+
+  // These variants read a 4-byte integer of the corresponding signedness and
+  // store it in the 8-byte return type.
+  bool Read4Into8(uint64_t* v) WARN_UNUSED_RESULT;
+  bool Read4sInto8s(int64_t* v) WARN_UNUSED_RESULT;
+
+  // Advance the stream by this many bytes.
+  bool SkipBytes(int nbytes) WARN_UNUSED_RESULT;
+
+  const uint8_t* data() const { return buf_; }
+  size_t size() const { return size_; }
+  size_t pos() const { return pos_; }
+
+ protected:
+  const uint8_t* buf_;
+  size_t size_;
+  size_t pos_;
+
+  template<typename T> bool Read(T* t) WARN_UNUSED_RESULT;
+
+  CORE_DISALLOW_COPY_AND_ASSIGN(BufferReader);
+};
+
+}  // namespace wvcdm
+
+#endif  // CDM_BASE_BUFFER_READER_H_