1// Copyright 2009 Google Inc.
2// Author: James deBoer
3//
4// Licensed under the Apache License, Version 2.0 (the "License");
5// you may not use this file except in compliance with the License.
6// You may obtain a copy of the License at
7//
8//      http://www.apache.org/licenses/LICENSE-2.0
9//
10// Unless required by applicable law or agreed to in writing, software
11// distributed under the License is distributed on an "AS IS" BASIS,
12// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13// See the License for the specific language governing permissions and
14// limitations under the License.
15
16#include <config.h>
17#include <stdio.h>
18#include <string.h>
19#include <sstream>
20#include <string>
21#include "jsonwriter.h"
22#include "google/output_string.h"
23
24namespace open_vcdiff {
25
26JSONCodeTableWriter::JSONCodeTableWriter()
27  : output_called_(false) {}
28JSONCodeTableWriter::~JSONCodeTableWriter() {}
29
30bool JSONCodeTableWriter::Init(size_t /*dictionary_size*/) {
31  output_ = "[";
32  target_length_ = 0;
33  return true;
34}
35
36void JSONCodeTableWriter::Output(OutputStringInterface* out) {
37  output_called_ = true;
38  out->append(output_.data(), output_.size());
39  output_ = "";
40  target_length_ = 0;
41}
42
43void JSONCodeTableWriter::FinishEncoding(OutputStringInterface* out) {
44  if (output_called_) {
45    out->append("]", 1);
46  }
47}
48
49void JSONCodeTableWriter::JSONEscape(const char* data,
50                                     size_t size,
51                                     string* out) {
52  for (size_t i = 0; i < size; ++i) {
53    const char c = data[i];
54    switch (c) {
55      case '"': out->append("\\\"", 2); break;
56      case '\\': out->append("\\\\", 2); break;
57      case '\b': out->append("\\b", 2); break;
58      case '\f': out->append("\\f", 2); break;
59      case '\n': out->append("\\n", 2); break;
60      case '\r': out->append("\\r", 2); break;
61      case '\t': out->append("\\t", 2); break;
62      default:
63        // encode zero as unicode, also all control codes.
64        if (c < 32 || c >= 127) {
65          char unicode_code[8] = "";
66          snprintf(unicode_code, sizeof(unicode_code), "\\u%04x", c);
67          out->append(unicode_code, strlen(unicode_code));
68        } else {
69          out->push_back(c);
70        }
71    }
72  }
73}
74
75void JSONCodeTableWriter::Add(const char* data, size_t size) {
76  output_.push_back('\"');
77  JSONEscape(data, size, &output_);
78  output_.append("\",", 2);
79  target_length_ += size;
80}
81
82void JSONCodeTableWriter::Copy(int32_t offset, size_t size) {
83  std::ostringstream copy_code;
84  copy_code << offset << "," << size << ",";
85  output_.append(copy_code.str());
86  target_length_ += size;
87}
88
89void JSONCodeTableWriter::Run(size_t size, unsigned char byte) {
90  output_.push_back('\"');
91  output_.append(string(size, byte).data(), size);
92  output_.append("\",", 2);
93  target_length_ += size;
94}
95
96size_t JSONCodeTableWriter::target_length() const {
97  return target_length_;
98}
99
100void JSONCodeTableWriter::WriteHeader(OutputStringInterface *,
101                                      VCDiffFormatExtensionFlags) {
102  // The JSON format does not need a header.
103}
104
105}  // namespace open_vcdiff
106