src: move JSONWriter into its own file

The JSONWriter feature is not inherently related to the report
feature in any way.

As a drive-by fix, remove a number of unused header includes.

PR-URL: #32552
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Gus Caplan <me@gus.host>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>

node.gyp

@@ -560,6 +560,7 @@
         'src/js_native_api_v8.h',
         'src/js_native_api_v8_internals.h',
         'src/js_stream.cc',
+        'src/json_utils.cc',
         'src/module_wrap.cc',
         'src/node.cc',
         'src/node_api.cc',
@@ -644,6 +645,7 @@
         'src/histogram.h',
         'src/histogram-inl.h',
         'src/js_stream.h',
+        'src/json_utils.h',
         'src/large_pages/node_large_page.cc',
         'src/large_pages/node_large_page.h',
         'src/memory_tracker.h',
@@ -1141,7 +1143,7 @@
         'test/cctest/test_linked_binding.cc',
         'test/cctest/test_per_process.cc',
         'test/cctest/test_platform.cc',
-        'test/cctest/test_report_util.cc',
+        'test/cctest/test_json_utils.cc',
         'test/cctest/test_sockaddr.cc',
         'test/cctest/test_traced_value.cc',
         'test/cctest/test_util.cc',

src/json_utils.cc

@@ -0,0 +1,67 @@
+#include "json_utils.h"
+
+namespace node {
+
+std::string EscapeJsonChars(const std::string& str) {
+  const std::string control_symbols[0x20] = {
+      "\\u0000", "\\u0001", "\\u0002", "\\u0003", "\\u0004", "\\u0005",
+      "\\u0006", "\\u0007", "\\b", "\\t", "\\n", "\\v", "\\f", "\\r",
+      "\\u000e", "\\u000f", "\\u0010", "\\u0011", "\\u0012", "\\u0013",
+      "\\u0014", "\\u0015", "\\u0016", "\\u0017", "\\u0018", "\\u0019",
+      "\\u001a", "\\u001b", "\\u001c", "\\u001d", "\\u001e", "\\u001f"
+  };
+
+  std::string ret;
+  size_t last_pos = 0;
+  size_t pos = 0;
+  for (; pos < str.size(); ++pos) {
+    std::string replace;
+    char ch = str[pos];
+    if (ch == '\\') {
+      replace = "\\\\";
+    } else if (ch == '\"') {
+      replace = "\\\"";
+    } else {
+      size_t num = static_cast<size_t>(ch);
+      if (num < 0x20) replace = control_symbols[num];
+    }
+    if (!replace.empty()) {
+      if (pos > last_pos) {
+        ret += str.substr(last_pos, pos - last_pos);
+      }
+      last_pos = pos + 1;
+      ret += replace;
+    }
+  }
+  // Append any remaining symbols.
+  if (last_pos < str.size()) {
+    ret += str.substr(last_pos, pos - last_pos);
+  }
+  return ret;
+}
+
+std::string Reindent(const std::string& str, int indent_depth) {
+  std::string indent;
+  for (int i = 0; i < indent_depth; i++) indent += ' ';
+
+  std::string out;
+  std::string::size_type pos = 0;
+  do {
+    std::string::size_type prev_pos = pos;
+    pos = str.find('\n', pos);
+
+    out.append(indent);
+
+    if (pos == std::string::npos) {
+      out.append(str, prev_pos, std::string::npos);
+      break;
+    } else {
+      pos++;
+      out.append(str, prev_pos, pos - prev_pos);
+    }
+  } while (true);
+
+  return out;
+}
+
+}  // namespace node

src/json_utils.h

@@ -0,0 +1,160 @@
+#ifndef SRC_JSON_UTILS_H_
+#define SRC_JSON_UTILS_H_
+
+#if defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS
+
+#include <iomanip>
+#include <ostream>
+#include <limits>
+
+namespace node {
+
+std::string EscapeJsonChars(const std::string& str);
+std::string Reindent(const std::string& str, int indentation);
+
+// JSON compiler definitions.
+class JSONWriter {
+ public:
+  JSONWriter(std::ostream& out, bool compact)
+    : out_(out), compact_(compact) {}
+
+ private:
+  inline void indent() { indent_ += 2; }
+  inline void deindent() { indent_ -= 2; }
+  inline void advance() {
+    if (compact_) return;
+    for (int i = 0; i < indent_; i++) out_ << ' ';
+  }
+  inline void write_one_space() {
+    if (compact_) return;
+    out_ << ' ';
+  }
+  inline void write_new_line() {
+    if (compact_) return;
+    out_ << '\n';
+  }
+
+ public:
+  inline void json_start() {
+    if (state_ == kAfterValue) out_ << ',';
+    write_new_line();
+    advance();
+    out_ << '{';
+    indent();
+    state_ = kObjectStart;
+  }
+
+  inline void json_end() {
+    write_new_line();
+    deindent();
+    advance();
+    out_ << '}';
+    state_ = kAfterValue;
+  }
+  template <typename T>
+  inline void json_objectstart(T key) {
+    if (state_ == kAfterValue) out_ << ',';
+    write_new_line();
+    advance();
+    write_string(key);
+    out_ << ':';
+    write_one_space();
+    out_ << '{';
+    indent();
+    state_ = kObjectStart;
+  }
+
+  template <typename T>
+  inline void json_arraystart(T key) {
+    if (state_ == kAfterValue) out_ << ',';
+    write_new_line();
+    advance();
+    write_string(key);
+    out_ << ':';
+    write_one_space();
+    out_ << '[';
+    indent();
+    state_ = kObjectStart;
+  }
+  inline void json_objectend() {
+    write_new_line();
+    deindent();
+    advance();
+    out_ << '}';
+    if (indent_ == 0) {
+      // Top-level object is complete, so end the line.
+      out_ << '\n';
+    }
+    state_ = kAfterValue;
+  }
+
+  inline void json_arrayend() {
+    write_new_line();
+    deindent();
+    advance();
+    out_ << ']';
+    state_ = kAfterValue;
+  }
+  template <typename T, typename U>
+  inline void json_keyvalue(const T& key, const U& value) {
+    if (state_ == kAfterValue) out_ << ',';
+    write_new_line();
+    advance();
+    write_string(key);
+    out_ << ':';
+    write_one_space();
+    write_value(value);
+    state_ = kAfterValue;
+  }
+
+  template <typename U>
+  inline void json_element(const U& value) {
+    if (state_ == kAfterValue) out_ << ',';
+    write_new_line();
+    advance();
+    write_value(value);
+    state_ = kAfterValue;
+  }
+
+  struct Null {};  // Usable as a JSON value.
+
+  struct ForeignJSON {
+    std::string as_string;
+  };
+
+ private:
+  template <typename T,
+            typename test_for_number = typename std::
+                enable_if<std::numeric_limits<T>::is_specialized, bool>::type>
+  inline void write_value(T number) {
+    if (std::is_same<T, bool>::value)
+      out_ << (number ? "true" : "false");
+    else
+      out_ << number;
+  }
+
+  inline void write_value(Null null) { out_ << "null"; }
+  inline void write_value(const char* str) { write_string(str); }
+  inline void write_value(const std::string& str) { write_string(str); }
+
+  inline void write_value(const ForeignJSON& json) {
+    out_ << Reindent(json.as_string, indent_);
+  }
+
+  inline void write_string(const std::string& str) {
+    out_ << '"' << EscapeJsonChars(str) << '"';
+  }
+  inline void write_string(const char* str) { write_string(std::string(str)); }
+
+  enum JSONState { kObjectStart, kAfterValue };
+  std::ostream& out_;
+  bool compact_;
+  int indent_ = 0;
+  int state_ = kObjectStart;
+};
+
+}  // namespace node
+
+#endif  // defined(NODE_WANT_INTERNALS) && NODE_WANT_INTERNALS
+
+#endif  // SRC_JSON_UTILS_H_

src/node_report.cc

@@ -1,4 +1,5 @@
 #include "env-inl.h"
+#include "json_utils.h"
 #include "node_report.h"
 #include "debug_utils-inl.h"
 #include "diagnosticfilename-inl.h"
@@ -16,6 +17,7 @@
 #include <dlfcn.h>
 #endif
 
+#include <iostream>
 #include <cstring>
 #include <ctime>
 #include <cwctype>
@@ -30,6 +32,7 @@ using node::arraysize;
 using node::ConditionVariable;
 using node::DiagnosticFilename;
 using node::Environment;
+using node::JSONWriter;
 using node::Mutex;
 using node::NativeSymbolDebuggingContext;
 using node::TIME_TYPE;