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diff --git a/sdch/open-vcdiff/src/vcencoder.cc b/sdch/open-vcdiff/src/vcencoder.cc
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+// Copyright 2007 Google Inc.
+// Author: Lincoln Smith
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// Classes to implement an Encoder for the format described in
+// RFC 3284 - The VCDIFF Generic Differencing and Compression Data Format.
+// The RFC text can be found at http://www.faqs.org/rfcs/rfc3284.html
+//
+// The RFC describes the possibility of using a secondary compressor
+// to further reduce the size of each section of the VCDIFF output.
+// That feature is not supported in this implementation of the encoder
+// and decoder.
+// No secondary compressor types have been publicly registered with
+// the IANA at http://www.iana.org/assignments/vcdiff-comp-ids
+// in the more than five years since the registry was created, so there
+// is no standard set of compressor IDs which would be generated by other
+// encoders or accepted by other decoders.
+
+#include <config.h>
+#include "google/vcencoder.h"
+#include <vector>
+#include "checksum.h"
+#include "encodetable.h"
+#include "logging.h"
+#include "google/output_string.h"
+#include "vcdiffengine.h"
+
+namespace open_vcdiff {
+
+HashedDictionary::HashedDictionary(const char* dictionary_contents,
+                                   size_t dictionary_size)
+    : engine_(new VCDiffEngine(dictionary_contents, dictionary_size)) { }
+
+HashedDictionary::~HashedDictionary() { delete engine_; }
+
+bool HashedDictionary::Init() {
+  return const_cast<VCDiffEngine*>(engine_)->Init();
+}
+
+class VCDiffStreamingEncoderImpl {
+ public:
+  VCDiffStreamingEncoderImpl(const HashedDictionary* dictionary,
+                             VCDiffFormatExtensionFlags format_extensions,
+                             bool look_for_target_matches);
+
+  // These functions are identical to their counterparts
+  // in VCDiffStreamingEncoder.
+  bool StartEncoding(OutputStringInterface* out);
+
+  bool EncodeChunk(const char* data, size_t len, OutputStringInterface* out);
+
+  bool FinishEncoding(OutputStringInterface* out);
+
+  const std::vector<int>& match_counts() const {
+    return coder_.match_counts();
+  }
+
+ private:
+  // Write the header (as defined in section 4.1 of the RFC) to *output.
+  // This includes information that can be gathered
+  // before the first chunk of input is available.
+  void WriteHeader(OutputStringInterface* output) const;
+
+  const VCDiffEngine* engine_;
+
+  // This implementation of the encoder uses the default
+  // code table.  A VCDiffCodeTableWriter could also be constructed
+  // using a custom code table.
+  VCDiffCodeTableWriter coder_;
+
+  const VCDiffFormatExtensionFlags format_extensions_;
+
+  // Determines whether to look for matches within the previously encoded
+  // target data, or just within the source (dictionary) data.  Please see
+  // vcencoder.h for a full explanation of this parameter.
+  const bool look_for_target_matches_;
+
+  // This state variable is used to ensure that StartEncoding(), EncodeChunk(),
+  // and FinishEncoding() are called in the correct order.  It will be true
+  // if StartEncoding() has been called, followed by zero or more calls to
+  // EncodeChunk(), but FinishEncoding() has not yet been called.  It will
+  // be false initially, and also after FinishEncoding() has been called.
+  bool encode_chunk_allowed_;
+
+  // Making these private avoids implicit copy constructor & assignment operator
+  VCDiffStreamingEncoderImpl(const VCDiffStreamingEncoderImpl&);  // NOLINT
+  void operator=(const VCDiffStreamingEncoderImpl&);
+};
+
+inline VCDiffStreamingEncoderImpl::VCDiffStreamingEncoderImpl(
+    const HashedDictionary* dictionary,
+    VCDiffFormatExtensionFlags format_extensions,
+    bool look_for_target_matches)
+    : engine_(dictionary->engine()),
+      coder_((format_extensions & VCD_FORMAT_INTERLEAVED) != 0),
+      format_extensions_(format_extensions),
+      look_for_target_matches_(look_for_target_matches),
+      encode_chunk_allowed_(false) { }
+
+inline void VCDiffStreamingEncoderImpl::WriteHeader(
+    OutputStringInterface* output) const {
+  DeltaFileHeader header_data = {
+    0xD6,  // Header1: "V" | 0x80
+    0xC3,  // Header2: "C" | 0x80
+    0xC4,  // Header3: "D" | 0x80
+    0x00,  // Header4: Draft standard format
+    0x00 };  // Hdr_Indicator:
+             // No compression, no custom code table
+  if (format_extensions_ != VCD_STANDARD_FORMAT) {
+    header_data.header4 = 'S';  // Header4: VCDIFF/SDCH, extensions used
+  }
+  output->append(reinterpret_cast<const char*>(&header_data),
+                 sizeof(header_data));
+  // If custom cache table sizes or a custom code table were used
+  // for encoding, here is where they would be appended to *output.
+  // This implementation of the encoder does not use those features,
+  // although the decoder can understand and interpret them.
+}
+
+inline bool VCDiffStreamingEncoderImpl::StartEncoding(
+    OutputStringInterface* out) {
+  if (!coder_.Init(engine_->dictionary_size())) {
+    LOG(DFATAL) << "Internal error: "
+                   "Initialization of code table writer failed" << LOG_ENDL;
+    return false;
+  }
+  WriteHeader(out);
+  encode_chunk_allowed_ = true;
+  return true;
+}
+
+inline bool VCDiffStreamingEncoderImpl::EncodeChunk(
+    const char* data,
+    size_t len,
+    OutputStringInterface* out) {
+  if (!encode_chunk_allowed_) {
+    LOG(ERROR) << "EncodeChunk called before StartEncoding" << LOG_ENDL;
+    return false;
+  }
+  if ((format_extensions_ & VCD_FORMAT_CHECKSUM) != 0) {
+    coder_.AddChecksum(ComputeAdler32(data, len));
+  }
+  engine_->Encode(data, len, look_for_target_matches_, out, &coder_);
+  return true;
+}
+
+inline bool VCDiffStreamingEncoderImpl::FinishEncoding(
+    OutputStringInterface* /*out*/) {
+  if (!encode_chunk_allowed_) {
+    LOG(ERROR) << "FinishEncoding called before StartEncoding" << LOG_ENDL;
+    return false;
+  }
+  encode_chunk_allowed_ = false;
+  // There should not be any need to output more data
+  // since EncodeChunk() encodes a complete target window
+  // and there is no end-of-delta-file marker.
+  return true;
+}
+
+VCDiffStreamingEncoder::VCDiffStreamingEncoder(
+    const HashedDictionary* dictionary,
+    VCDiffFormatExtensionFlags format_extensions,
+    bool look_for_target_matches)
+    : impl_(new VCDiffStreamingEncoderImpl(dictionary,
+                                           format_extensions,
+                                           look_for_target_matches)) { }
+
+VCDiffStreamingEncoder::~VCDiffStreamingEncoder() { delete impl_; }
+
+bool VCDiffStreamingEncoder::StartEncodingToInterface(
+    OutputStringInterface* out) {
+  return impl_->StartEncoding(out);
+}
+
+bool VCDiffStreamingEncoder::EncodeChunkToInterface(
+    const char* data,
+    size_t len,
+    OutputStringInterface* out) {
+  return impl_->EncodeChunk(data, len, out);
+}
+
+bool VCDiffStreamingEncoder::FinishEncodingToInterface(
+    OutputStringInterface* out) {
+  return impl_->FinishEncoding(out);
+}
+
+void VCDiffStreamingEncoder::GetMatchCounts(
+    std::vector<int>* match_counts) const {
+  if (!match_counts) {
+    LOG(DFATAL) << "GetMatchCounts() called with NULL argument" << LOG_ENDL;
+    return;
+  }
+  *match_counts = impl_->match_counts();
+}
+
+bool VCDiffEncoder::EncodeToInterface(const char* target_data,
+                                      size_t target_len,
+                                      OutputStringInterface* out) {
+  out->clear();
+  if (!encoder_) {
+    if (!dictionary_.Init()) {
+      LOG(ERROR) << "Error initializing HashedDictionary" << LOG_ENDL;
+      return false;
+    }
+    encoder_ = new VCDiffStreamingEncoder(&dictionary_,
+                                          flags_,
+                                          look_for_target_matches_);
+  }
+  if (!encoder_->StartEncodingToInterface(out)) {
+    return false;
+  }
+  if (!encoder_->EncodeChunkToInterface(target_data, target_len, out)) {
+    return false;
+  }
+  return encoder_->FinishEncodingToInterface(out);
+}
+
+}  // namespace open_vcdiff