CL for perf tryjob on linux

third_party/cld/encodings/internal/encodings.cc

-// Copyright (c) 2006-2009 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
+// Copyright 2008 Google Inc. All Rights Reserved.
+// Author: jrm@google.com (Jim Meehan)
 
 #include "encodings/public/encodings.h"
 
-
-// We do not use it, just to please a compiler and minimize ported
-// code changes.
+#include <string.h>                     // for strcasecmp
+//#include <hash_map>                     // for _Hashtable_iterator, etc
+#include <utility>                      // for pair
+
+//#include "base/googleinit.h"            // for REGISTER_MODULE_INITIALIZER
+//#include "base/logging.h"               // for operator<<, Check_EQImpl, etc
+//#include "base/macros.h"                // for COMPILE_ASSERT, etc
+//#include "base/mutex.h"                 // for Mutex, MutexLock
+//#include "util/hash/case_insensitive_hash.h"
+//#include "util/hash/hash.h"
+#include "encodings/compact_lang_det/win/cld_basictypes.h"
+#include "encodings/compact_lang_det/win/cld_logging.h"
+#include "encodings/compact_lang_det/win/cld_macros.h"
+
+struct EncodingInfo {
+  // The standard name for this encoding.
+  //
+  const char* encoding_name_;
+
+  // The "preferred MIME name" of an encoding as specified by the IANA at:
+  //     http://www.iana.org/assignments/character-sets
+  //
+  //   Note that the preferred MIME name may differ slightly from the
+  //   official IANA name: i.e. ISO-8859-1 vs. ISO_8859-1:1987
+  //
+  const char* mime_encoding_name_;
+
+  // NOTE: As of January 2007, it is a Google requirement that if an
+  // encoding has an IANA name, then encoding_name_ and
+  // mime_encoding_name_ must be the same string.
+  //
+  // However, there can be exceptions if there are compelling reasons.
+  // For example, Japanese mobile handsets require the name
+  // "Shift_JIS" in charset=... parameter in Content-Type headers to
+  // process emoji (emoticons) in their private encodings.  In that
+  // case, mime_encoding_name_ should be "Shift_JIS", despite
+  // encoding_name_ actually is "X-KDDI-Shift_JIS".
+
+  // Some multi-byte encodings use byte values that coincide with the
+  // ASCII codes for HTML syntax characters <>"&' and browsers like MSIE
+  // can misinterpret these, as indicated in an external XSS report from
+  // 2007-02-15. Here, we map these dangerous encodings to safer ones. We
+  // also use UTF8 instead of encodings that we don't support in our
+  // output, and we generally try to be conservative in what we send out.
+  // Where the client asks for single- or double-byte encodings that are
+  // not as common, we substitute a more common single- or double-byte
+  // encoding, if there is one, thereby preserving the client's intent
+  // to use less space than UTF-8. This also means that characters
+  // outside the destination set will be converted to HTML NCRs (&#NNN;)
+  // if requested.
+
+  Encoding preferred_web_output_encoding_;
+};
+
+static const EncodingInfo kEncodingInfoTable[] = {
+  { "ASCII", "ISO-8859-1", ISO_8859_1},
+  { "Latin2", "ISO-8859-2", ISO_8859_2},
+  { "Latin3", "ISO-8859-3", UTF8},
+      // MSIE 6 does not support ISO-8859-3 (XSS issue)
+  { "Latin4", "ISO-8859-4", ISO_8859_4},
+  { "ISO-8859-5", "ISO-8859-5", ISO_8859_5},
+  { "Arabic", "ISO-8859-6", ISO_8859_6},
+  { "Greek", "ISO-8859-7", ISO_8859_7},
+  { "Hebrew", "ISO-8859-8", MSFT_CP1255},
+      // we do not endorse the visual order
+  { "Latin5", "ISO-8859-9", ISO_8859_9},
+  { "Latin6", "ISO-8859-10", UTF8},
+      // MSIE does not support ISO-8859-10 (XSS issue)
+  { "EUC-JP",  "EUC-JP", JAPANESE_EUC_JP},
+  { "SJS", "Shift_JIS", JAPANESE_SHIFT_JIS},
+  { "JIS", "ISO-2022-JP", JAPANESE_SHIFT_JIS},
+      // due to potential confusion with HTML syntax chars
+  { "BIG5", "Big5", CHINESE_BIG5},
+  { "GB",  "GB2312", CHINESE_GB},
+  { "EUC-CN",
+        "EUC-CN",
+        // Misnamed. Should be EUC-TW.
+        CHINESE_BIG5},
+      // MSIE treats "EUC-CN" like GB2312, which is not EUC-TW,
+      // and EUC-TW is rare, so we prefer Big5 for output.
+  { "KSC", "EUC-KR", KOREAN_EUC_KR},
+  { "Unicode",
+    "UTF-16LE",
+        // Internet Explorer doesn't recognize "ISO-10646-UCS-2"
+        UTF8
+        // due to potential confusion with HTML syntax chars
+        },
+  { "EUC",
+        "EUC",  // Misnamed. Should be EUC-TW.
+        CHINESE_BIG5
+        // MSIE does not recognize "EUC" (XSS issue),
+        // and EUC-TW is rare, so we prefer Big5 for output.
+        },
+  { "CNS",
+        "CNS",  // Misnamed. Should be EUC-TW.
+        CHINESE_BIG5},
+      // MSIE does not recognize "CNS" (XSS issue),
+      // and EUC-TW is rare, so we prefer Big5 for output.
+  { "BIG5-CP950",
+        "BIG5-CP950",  // Not an IANA name
+        CHINESE_BIG5
+        // MSIE does not recognize "BIG5-CP950" (XSS issue)
+        },
+  { "CP932", "CP932",  // Not an IANA name
+        JAPANESE_SHIFT_JIS},  // MSIE does not recognize "CP932" (XSS issue)
+  { "UTF8", "UTF-8", UTF8},
+  { "Unknown",
+        "x-unknown",  // Not an IANA name
+        UTF8},  // UTF-8 is our default output encoding
+  { "ASCII-7-bit", "US-ASCII", ASCII_7BIT},
+  { "KOI8R", "KOI8-R", RUSSIAN_KOI8_R},
+  { "CP1251", "windows-1251", RUSSIAN_CP1251},
+  { "CP1252", "windows-1252", MSFT_CP1252},
+  { "KOI8U",
+        "KOI8-U",
+        ISO_8859_5},  // because koi8-u is not as common
+  { "CP1250", "windows-1250", MSFT_CP1250},
+  { "ISO-8859-15", "ISO-8859-15", ISO_8859_15},
+  { "CP1254", "windows-1254", MSFT_CP1254},
+  { "CP1257", "windows-1257", MSFT_CP1257},
+  { "ISO-8859-11", "ISO-8859-11", ISO_8859_11},
+  { "CP874", "windows-874", MSFT_CP874},
+  { "CP1256", "windows-1256", MSFT_CP1256},
+  { "CP1255", "windows-1255", MSFT_CP1255},
+  { "ISO-8859-8-I", "ISO-8859-8-I", MSFT_CP1255},
+      // Java does not support iso-8859-8-i
+  { "VISUAL", "ISO-8859-8", MSFT_CP1255},
+      // we do not endorse the visual order
+  { "CP852", "cp852", MSFT_CP1250},
+      // because cp852 is not as common
+  { "CSN_369103", "csn_369103", MSFT_CP1250},
+      // MSIE does not recognize "csn_369103" (XSS issue)
+  { "CP1253", "windows-1253", MSFT_CP1253},
+  { "CP866", "IBM866", RUSSIAN_CP1251},
+      // because cp866 is not as common
+  { "ISO-8859-13", "ISO-8859-13", UTF8},
+      // because iso-8859-13 is not widely supported
+  { "ISO-2022-KR", "ISO-2022-KR", KOREAN_EUC_KR},
+      // due to potential confusion with HTML syntax chars
+  { "GBK", "GBK", GBK},
+  { "GB18030", "GB18030", GBK},
+      // because gb18030 is not widely supported
+  { "BIG5_HKSCS", "BIG5-HKSCS", CHINESE_BIG5},
+      // because Big5-HKSCS is not widely supported
+  { "ISO_2022_CN", "ISO-2022-CN", CHINESE_GB},
+      // due to potential confusion with HTML syntax chars
+  { "TSCII", "tscii", UTF8},
+      // we do not have an output converter for this font encoding
+  { "TAM", "tam", UTF8},
+      // we do not have an output converter for this font encoding
+  { "TAB", "tab", UTF8},
+      // we do not have an output converter for this font encoding
+  { "JAGRAN", "jagran", UTF8},
+      // we do not have an output converter for this font encoding
+  { "MACINTOSH", "MACINTOSH", ISO_8859_1},
+      // because macintosh is relatively uncommon
+  { "UTF7", "UTF-7",
+        UTF8},  // UTF-7 has been the subject of XSS attacks and is deprecated
+  { "BHASKAR", "bhaskar",
+        UTF8},  // we do not have an output converter for this font encoding
+  { "HTCHANAKYA", "htchanakya",  // not an IANA charset name.
+        UTF8},  // we do not have an output converter for this font encoding
+  { "UTF-16BE", "UTF-16BE",
+        UTF8},  // due to potential confusion with HTML syntax chars
+  { "UTF-16LE", "UTF-16LE",
+        UTF8},  // due to potential confusion with HTML syntax chars
+  { "UTF-32BE", "UTF-32BE",
+        UTF8},  // unlikely to cause XSS bugs, but very uncommon on Web
+  { "UTF-32LE", "UTF-32LE",
+        UTF8},  // unlikely to cause XSS bugs, but very uncommon on Web
+  { "X-BINARYENC", "x-binaryenc",  // Not an IANA name
+        UTF8},  // because this one is not intended for output (just input)
+  { "HZ-GB-2312", "HZ-GB-2312",
+        CHINESE_GB},  // due to potential confusion with HTML syntax chars
+  { "X-UTF8UTF8", "x-utf8utf8",  // Not an IANA name
+        UTF8},  // because this one is not intended for output (just input)
+  { "X-TAM-ELANGO", "x-tam-elango",
+        UTF8},  // we do not have an output converter for this font encoding
+  { "X-TAM-LTTMBARANI", "x-tam-lttmbarani",
+        UTF8},  // we do not have an output converter for this font encoding
+  { "X-TAM-SHREE", "x-tam-shree",
+        UTF8},  // we do not have an output converter for this font encoding
+  { "X-TAM-TBOOMIS", "x-tam-tboomis",
+        UTF8},  // we do not have an output converter for this font encoding
+  { "X-TAM-TMNEWS", "x-tam-tmnews",
+        UTF8},  // we do not have an output converter for this font encoding
+  { "X-TAM-WEBTAMIL", "x-tam-webtamil",
+        UTF8},  // we do not have an output converter for this font encoding
+
+  { "X-KDDI-Shift_JIS", "Shift_JIS", JAPANESE_SHIFT_JIS},
+      // KDDI version of Shift_JIS with Google Emoji PUA mappings.
+      // Note that MimeEncodingName() returns "Shift_JIS", since KDDI uses
+      // "Shift_JIS" in HTTP headers and email messages.
+
+  { "X-DoCoMo-Shift_JIS", "Shift_JIS", JAPANESE_SHIFT_JIS},
+      // DoCoMo version of Shift_JIS with Google Emoji PUA mappings.
+      // See the comment at KDDI_SHIFT_JIS for other issues.
+
+  { "X-SoftBank-Shift_JIS", "Shift_JIS", JAPANESE_SHIFT_JIS},
+      // SoftBank version of Shift_JIS with Google Emoji PUA mappings.
+      // See the comment at KDDI_SHIFT_JIS for other issues.
+
+  { "X-KDDI-ISO-2022-JP", "ISO-2022-JP", JAPANESE_SHIFT_JIS},
+      // KDDI version of ISO-2022-JP with Google Emoji PUA mappings.
+      // See the comment at KDDI_SHIFT_JIS for other issues.
+      // The preferred Web encoding is due to potential confusion with
+      // HTML syntax chars.
+
+  { "X-SoftBank-ISO-2022-JP", "ISO-2022-JP", JAPANESE_SHIFT_JIS},
+      // SoftBank version of ISO-2022-JP with Google Emoji PUA mappings.
+      // See the comment at KDDI_SHIFT_JIS for other issues.
+      // The preferred Web encoding is due to potential confusion with
+      // HTML syntax chars.
+
+      // Please refer to NOTE: section in the comments in the definition
+      // of "struct I18NInfoByEncoding", before adding new encodings.
+
+};
+
+
+
+COMPILE_ASSERT(arraysize(kEncodingInfoTable) == NUM_ENCODINGS,
+               kEncodingInfoTable_has_incorrect_size);
+
+Encoding default_encoding() {return LATIN1;}
+
+// *************************************************************
+// Encoding predicates
+//   IsValidEncoding()
+//   IsEncEncCompatible
+//   IsEncodingWithSupportedLanguage
+//   IsSupersetOfAscii7Bit
+//   Is8BitEncoding
+//   IsCJKEncoding
+//   IsHebrewEncoding
+//   IsRightToLeftEncoding
+//   IsLogicalRightToLeftEncoding
+//   IsVisualRightToLeftEncoding
+//   IsIso2022Encoding
+//   IsIso2022JpOrVariant
+//   IsShiftJisOrVariant
+//   IsJapaneseCellPhoneCarrierSpecificEncoding
+// *************************************************************
+
+bool IsValidEncoding(Encoding enc) {
+  return ((enc >= 0) && (enc < kNumEncodings));
+}
+
+bool IsEncEncCompatible(const Encoding from, const Encoding to) {
+  // Tests compatibility between the "from" and "to" encodings; in
+  // the typical case -- when both are valid known encodings -- this
+  // returns true iff converting from first to second is a no-op.
+  if (!IsValidEncoding(from) || !IsValidEncoding(to)) {
+    return false;  // we only work with valid encodings...
+  } else if (to == from) {
+    return true;   // the trivial common case
+  }
+
+  if (to == UNKNOWN_ENCODING) {
+    return true;   // all valid encodings are compatible with the unknown
+  }
+
+  if (from == UNKNOWN_ENCODING) {
+    return false;  // no unknown encoding is compatible with one that is
+  }
+
+  if (from == ASCII_7BIT) {
+    return IsSupersetOfAscii7Bit(to);
+  }
+
+  return (from == ISO_8859_1 && to == MSFT_CP1252) ||
+         (from == ISO_8859_8 && to == HEBREW_VISUAL) ||
+         (from == HEBREW_VISUAL && to == ISO_8859_8) ||
+         (from == ISO_8859_9 && to == MSFT_CP1254) ||
+         (from == ISO_8859_11 && to == MSFT_CP874) ||
+         (from == JAPANESE_SHIFT_JIS && to == JAPANESE_CP932) ||
+         (from == CHINESE_BIG5 && to == CHINESE_BIG5_CP950) ||
+         (from == CHINESE_GB && to == GBK) ||
+         (from == CHINESE_GB && to == GB18030) ||
+         (from == CHINESE_EUC_CN && to == CHINESE_EUC_DEC) ||
+         (from == CHINESE_EUC_CN && to == CHINESE_CNS) ||
+         (from == CHINESE_EUC_DEC && to == CHINESE_EUC_CN) ||
+         (from == CHINESE_EUC_DEC && to == CHINESE_CNS) ||
+         (from == CHINESE_CNS && to == CHINESE_EUC_CN) ||
+         (from == CHINESE_CNS && to == CHINESE_EUC_DEC);
+}
+
+// To be a superset of 7-bit Ascii means that bytes 0...127 in the given
+// encoding represent the same characters as they do in ISO_8859_1.
+
+// TODO: This list could be expanded.  Many other encodings are supersets
+// of 7-bit Ascii.  In fact, Japanese JIS and Unicode are the only two
+// encodings that I know for a fact should *not* be in this list.
+bool IsSupersetOfAscii7Bit(Encoding e) {
+  switch (e) {
+    case ISO_8859_1:
+    case ISO_8859_2:
+    case ISO_8859_3:
+    case ISO_8859_4:
+    case ISO_8859_5:
+    case ISO_8859_6:
+    case ISO_8859_7:
+    case ISO_8859_8:
+    case ISO_8859_9:
+    case ISO_8859_10:
+    case JAPANESE_EUC_JP:
+    case JAPANESE_SHIFT_JIS:
+    case CHINESE_BIG5:
+    case CHINESE_GB:
+    case CHINESE_EUC_CN:
+    case KOREAN_EUC_KR:
+    case CHINESE_EUC_DEC:
+    case CHINESE_CNS:
+    case CHINESE_BIG5_CP950:
+    case JAPANESE_CP932:
+    case UTF8:
+    case UNKNOWN_ENCODING:
+    case ASCII_7BIT:
+    case RUSSIAN_KOI8_R:
+    case RUSSIAN_CP1251:
+    case MSFT_CP1252:
+    case RUSSIAN_KOI8_RU:
+    case MSFT_CP1250:
+    case ISO_8859_15:
+    case MSFT_CP1254:
+    case MSFT_CP1257:
+    case ISO_8859_11:
+    case MSFT_CP874:
+    case MSFT_CP1256:
+    case MSFT_CP1255:
+    case ISO_8859_8_I:
+    case HEBREW_VISUAL:
+    case CZECH_CP852:
+    case MSFT_CP1253:
+    case RUSSIAN_CP866:
+    case ISO_8859_13:
+    case GBK:
+    case GB18030:
+    case BIG5_HKSCS:
+    case MACINTOSH_ROMAN:
+      return true;
+    default:
+      return false;
+  }
+}
+
+// To be an 8-bit encoding means that there are fewer than 256 symbols.
+// Each byte determines a new character; there are no multi-byte sequences.
+
+// TODO: This list could maybe be expanded.  Other encodings may be 8-bit.
+bool Is8BitEncoding(Encoding e) {
+  switch (e) {
+    case ASCII_7BIT:
+    case ISO_8859_1:
+    case ISO_8859_2:
+    case ISO_8859_3:
+    case ISO_8859_4:
+    case ISO_8859_5:
+    case ISO_8859_6:
+    case ISO_8859_7:
+    case ISO_8859_8:
+    case ISO_8859_8_I:
+    case ISO_8859_9:
+    case ISO_8859_10:
+    case ISO_8859_11:
+    case ISO_8859_13:
+    case ISO_8859_15:
+    case MSFT_CP1252:
+    case MSFT_CP1253:
+    case MSFT_CP1254:
+    case MSFT_CP1255:
+    case MSFT_CP1256:
+    case MSFT_CP1257:
+    case RUSSIAN_KOI8_R:
+    case RUSSIAN_KOI8_RU:
+    case RUSSIAN_CP866:
+      return true;
+    default:
+      return false;
+  }
+}
+
+bool IsCJKEncoding(Encoding e) {
+  switch (e) {
+    case JAPANESE_EUC_JP:
+    case JAPANESE_SHIFT_JIS:
+    case JAPANESE_JIS:
+    case CHINESE_BIG5:
+    case CHINESE_GB:
+    case CHINESE_EUC_CN:
+    case KOREAN_EUC_KR:
+    case CHINESE_EUC_DEC:
+    case CHINESE_CNS:
+    case CHINESE_BIG5_CP950:
+    case JAPANESE_CP932:
+    case ISO_2022_KR:
+    case GBK:
+    case GB18030:
+    case BIG5_HKSCS:
+    case ISO_2022_CN:
+    case HZ_GB_2312:
+      return true;
+    default:
+      return false;
+  }
+}
+
+bool IsHebrewEncoding(Encoding e) {
+  return (e == ISO_8859_8 ||
+          e == ISO_8859_8_I ||
+          e == MSFT_CP1255 ||
+          e == HEBREW_VISUAL);
+}
+
+
+
+bool IsRightToLeftEncoding(Encoding enc) {
+  switch (enc) {
+    case MSFT_CP1255:
+    case MSFT_CP1256:
+    case ARABIC_ENCODING:
+    case HEBREW_ENCODING:
+    case ISO_8859_8_I:
+    case HEBREW_VISUAL:
+      return true;
+    default:
+      return false;
+  }
+}
+
+bool IsLogicalRightToLeftEncoding(Encoding enc) {
+  return IsRightToLeftEncoding(enc) && !IsVisualRightToLeftEncoding(enc);
+}
+
+// Note that despite an RFC to the contrary, ARABIC_ENCODING (ISO-8859-6)
+// is NOT visual.
+bool IsVisualRightToLeftEncoding(Encoding enc) {
+  switch (enc) {
+    case HEBREW_ENCODING:
+    case HEBREW_VISUAL:
+      return true;
+    default:
+      return false;
+  }
+}
+
+
+
+
+
+bool IsIso2022Encoding(Encoding enc) {
+  return (IsIso2022JpOrVariant(enc) ||
+          enc == ISO_2022_KR ||
+          enc == ISO_2022_CN);
+}
+
+bool IsIso2022JpOrVariant(Encoding enc) {
+  return (enc == JAPANESE_JIS ||
+          enc == KDDI_ISO_2022_JP ||
+          enc == SOFTBANK_ISO_2022_JP);
+}
+
+bool IsShiftJisOrVariant(Encoding enc) {
+  return (enc == JAPANESE_SHIFT_JIS ||
+          enc == JAPANESE_CP932 ||
+          enc == KDDI_SHIFT_JIS ||
+          enc == DOCOMO_SHIFT_JIS ||
+          enc == SOFTBANK_SHIFT_JIS);
+}
+
+bool IsJapaneseCellPhoneCarrierSpecificEncoding(Encoding enc) {
+  return (enc == KDDI_ISO_2022_JP ||
+          enc == KDDI_SHIFT_JIS ||
+          enc == DOCOMO_SHIFT_JIS ||
+          enc == SOFTBANK_SHIFT_JIS ||
+          enc == SOFTBANK_ISO_2022_JP);
+}
+
+
+// *************************************************************
+// ENCODING NAMES
+//   EncodingName() [Encoding to name]
+//   MimeEncodingName() [Encoding to name]
+//   EncodingFromName() [name to Encoding]
+//   EncodingNameAliasToEncoding() [name to Encoding]
+//   default_encoding_name()
+//   invalid_encoding_name()
+// *************************************************************
+
 const char * EncodingName(const Encoding enc) {
-  return "";
-}
+  if ( (enc < 0) || (enc >= kNumEncodings) )
+    return invalid_encoding_name();
+  return kEncodingInfoTable[enc].encoding_name_;
+}
+
+// TODO: Unify MimeEncodingName and EncodingName, or determine why
+// such a unification is not possible.
+
+const char * MimeEncodingName(Encoding enc) {
+  if ( (enc < 0) || (enc >= kNumEncodings) )
+    return "";  // TODO(jrm) Should this be invalid_encoding_name()?
+  return kEncodingInfoTable[enc].mime_encoding_name_;
+}
+
+bool EncodingFromName(const char* enc_name, Encoding *encoding) {
+  *encoding = UNKNOWN_ENCODING;
+  if ( enc_name == NULL ) return false;
+
+  for ( int i = 0; i < kNumEncodings; i++ ) {
+    if ( !strcasecmp(enc_name, kEncodingInfoTable[i].encoding_name_) ) {
+      *encoding = static_cast<Encoding>(i);
+      return true;
+    }
+  }
+  return false;
+}
+
+#if 0
+// The encoding_map maps standard and non-standard encoding-names
+// (strings) to Encoding enums. It is used only by
+// EncodingNameAliasToEncoding. Note that the map uses
+// case-insensitive hash and comparison functions.
+
+typedef hash_map <const char *, Encoding,
+                  CStringAlnumCaseHash,
+                  CStringAlnumCaseEqual> EncodingMap;
+
+static EncodingMap encoding_map;
+
+// Mutex for locking the code that initializes encoding_map.
+// static Mutex encodings_init_mutex(base::LINKER_INITIALIZED);
+
+void InitEncodings() {
+  // For thread safety, keep a mutex while initializing this map.
+  // Also allow this function to be called more than once and
+  // gracefully exiting if that occurs.
+  // MutexLock lock(&encodings_init_mutex);
+  if (!encoding_map.empty()) {
+    // Already initialized
+    return;
+  }
+
+  // Initialize the map with all the "standard" encoding names,
+  // i.e., the ones returned by EncodingName and MimeEncodingName.
+  //
+  // First, add internal encoding names returned by EncodingName().
+  for (int i = 0; i < NUM_ENCODINGS; ++i) {
+    Encoding e = static_cast<Encoding>(i);
+    // Internal encoding names must be unique.
+    // The internal names are guaranteed to be unique by the CHECK_EQ.
+    const char *encoding_name = EncodingName(e);
+    CHECK_EQ(0, encoding_map.count(encoding_name))
+        << "Duplicate found for " << encoding_name;
+    encoding_map[encoding_name] = e;
+  }
+  // Then, add mime encoding names returned by MimeEncodingName().
+  // We don't override existing entries, to give precedence to entries
+  // added earlier.
+  for (int i = 0; i < NUM_ENCODINGS; ++i) {
+    Encoding e = static_cast<Encoding>(i);
+    // Note that MimeEncodingName() can return the same mime encoding
+    // name for different encoding enums like JAPANESE_SHIFT_JIS and
+    // KDDI_SHIFT_JIS.  In that case, the encoding enum first seen
+    // will be the value for the encoding name in the map.
+    const char *mime_encoding_name = MimeEncodingName(e);
+    if (encoding_map.count(mime_encoding_name) == 0) {
+      encoding_map[mime_encoding_name] = e;
+    }
+  }
+
+  // Add some non-standard names: alternate spellings, common typos,
+  // etc. (It does no harm to add names already in the map.) Note
+  // that although the map is case-insensitive, by convention the
+  // keys are written here in lower case. For ease of maintenance,
+  // they are listed in alphabetical order.
+  encoding_map["5601"] = KOREAN_EUC_KR;
+  encoding_map["646"] = ASCII_7BIT;
+  encoding_map["852"] = CZECH_CP852;
+  encoding_map["866"] = RUSSIAN_CP866;
+  encoding_map["8859-1"] = ISO_8859_1;
+  encoding_map["ansi-1251"] = RUSSIAN_CP1251;
+  encoding_map["ansi_x3.4-1968"] = ASCII_7BIT;
+  encoding_map["arabic"] = ISO_8859_6;
+  encoding_map["ascii"] = ISO_8859_1;
+  encoding_map["ascii-7-bit"] = ASCII_7BIT;  // not iana standard
+  encoding_map["asmo-708"] = ISO_8859_6;
+  encoding_map["bhaskar"] = BHASKAR;
+  encoding_map["big5"] = CHINESE_BIG5;
+  encoding_map["big5-cp950"] = CHINESE_BIG5_CP950;  // not iana standard
+  encoding_map["big5-hkscs"] = BIG5_HKSCS;
+  encoding_map["chinese"] = CHINESE_GB;
+  encoding_map["cns"] = CHINESE_CNS;  // not iana standard
+  encoding_map["cns11643"] = CHINESE_CNS;
+  encoding_map["cp1250"] = MSFT_CP1250;  // not iana standard
+  encoding_map["cp1251"] = RUSSIAN_CP1251;  // not iana standard
+  encoding_map["cp1252"] = MSFT_CP1252;  // not iana standard
+  encoding_map["cp1253"] = MSFT_CP1253;  // not iana standard
+  encoding_map["cp1254"] = MSFT_CP1254;  // not iana standard
+  encoding_map["cp1255"] = MSFT_CP1255;
+  encoding_map["cp1256"] = MSFT_CP1256;
+  encoding_map["cp1257"] = MSFT_CP1257;  // not iana standard
+  encoding_map["cp819"] = ISO_8859_1;
+  encoding_map["cp852"] = CZECH_CP852;
+  encoding_map["cp866"] = RUSSIAN_CP866;
+  encoding_map["cp-866"] = RUSSIAN_CP866;
+  encoding_map["cp874"] = MSFT_CP874;
+  encoding_map["cp932"] = JAPANESE_CP932;  // not iana standard
+  encoding_map["cp950"] = CHINESE_BIG5_CP950;  // not iana standard
+  encoding_map["csbig5"] = CHINESE_BIG5;
+  encoding_map["cseucjpkdfmtjapanese"] = JAPANESE_EUC_JP;
+  encoding_map["cseuckr"] = KOREAN_EUC_KR;
+  encoding_map["csgb2312"] = CHINESE_GB;
+  encoding_map["csibm852"] = CZECH_CP852;
+  encoding_map["csibm866"] = RUSSIAN_CP866;
+  encoding_map["csiso2022jp"] = JAPANESE_JIS;
+  encoding_map["csiso2022kr"] = ISO_2022_KR;
+  encoding_map["csiso58gb231280"] = CHINESE_GB;
+  encoding_map["csiso88598i"] = ISO_8859_8_I;
+  encoding_map["csisolatin1"] = ISO_8859_1;
+  encoding_map["csisolatin2"] = ISO_8859_2;
+  encoding_map["csisolatin3"] = ISO_8859_3;
+  encoding_map["csisolatin4"] = ISO_8859_4;
+  encoding_map["csisolatin5"] = ISO_8859_9;
+  encoding_map["csisolatin6"] = ISO_8859_10;
+  encoding_map["csisolatinarabic"] = ISO_8859_6;
+  encoding_map["csisolatincyrillic"] = ISO_8859_5;
+  encoding_map["csisolatingreek"] = ISO_8859_7;
+  encoding_map["csisolatinhebrew"] = ISO_8859_8;
+  encoding_map["csksc56011987"] = KOREAN_EUC_KR;
+  encoding_map["csmacintosh"] = MACINTOSH_ROMAN;
+  encoding_map["csn-369103"] = CZECH_CSN_369103;
+  encoding_map["csshiftjis"] = JAPANESE_SHIFT_JIS;
+  encoding_map["csunicode"] = UTF16BE;
+  encoding_map["csunicode11"] = UTF16BE;
+  encoding_map["csunicode11utf7"] = UTF7;
+  encoding_map["csunicodeascii"] = UTF16BE;
+  encoding_map["csunicodelatin1"] = UTF16BE;
+  encoding_map["cyrillic"] = ISO_8859_5;
+  encoding_map["ecma-114"] = ISO_8859_6;
+  encoding_map["ecma-118"] = ISO_8859_7;
+  encoding_map["elot_928"] = ISO_8859_7;
+  encoding_map["euc"] = CHINESE_EUC_DEC;  // not iana standard
+  encoding_map["euc-cn"] = CHINESE_EUC_CN;  // not iana standard
+  encoding_map["euc-dec"] = CHINESE_EUC_DEC;  // not iana standard
+  encoding_map["euc-jp"] = JAPANESE_EUC_JP;
+  encoding_map["euc-kr"] = KOREAN_EUC_KR;
+  encoding_map["eucgb2312_cn"] = CHINESE_GB;
+  encoding_map["gb"] = CHINESE_GB;  // not iana standard
+  encoding_map["gb18030"] = GB18030;
+  encoding_map["gb2132"] = CHINESE_GB;  // common typo
+  encoding_map["gb2312"] = CHINESE_GB;
+  encoding_map["gb_2312-80"] = CHINESE_GB;
+  encoding_map["gbk"] = GBK;
+  encoding_map["greek"] = ISO_8859_7;
+  encoding_map["greek8"] = ISO_8859_7;
+  encoding_map["hebrew"] = ISO_8859_8;
+  encoding_map["htchanakya"] = HTCHANAKYA;
+  encoding_map["hz-gb-2312"] = HZ_GB_2312;
+  encoding_map["ibm819"] = ISO_8859_1;
+  encoding_map["ibm852"] = CZECH_CP852;
+  encoding_map["ibm874"] = MSFT_CP874;
+  encoding_map["iso-10646"] = UTF16BE;
+  encoding_map["iso-10646-j-1"] = UTF16BE;
+  encoding_map["iso-10646-ucs-2"] = UNICODE;
+  encoding_map["iso-10646-ucs-4"] = UTF32BE;
+  encoding_map["iso-10646-ucs-basic"] = UTF16BE;
+  encoding_map["iso-10646-unicode-latin1"] = UTF16BE;
+  encoding_map["iso-2022-cn"] = ISO_2022_CN;
+  encoding_map["iso-2022-jp"] = JAPANESE_JIS;
+  encoding_map["iso-2022-kr"] = ISO_2022_KR;
+  encoding_map["iso-8559-1"] = ISO_8859_1;      // common typo
+  encoding_map["iso-874"] = MSFT_CP874;
+  encoding_map["iso-8858-1"] = ISO_8859_1;      // common typo
+  // iso-8859-0 was a temporary name, eventually renamed iso-8859-15
+  encoding_map["iso-8859-0"] = ISO_8859_15;
+  encoding_map["iso-8859-1"] = ISO_8859_1;
+  encoding_map["iso-8859-10"] = ISO_8859_10;
+  encoding_map["iso-8859-11"] = ISO_8859_11;
+  encoding_map["iso-8859-13"] = ISO_8859_13;
+  encoding_map["iso-8859-15"] = ISO_8859_15;
+  encoding_map["iso-8859-2"] = ISO_8859_2;
+  encoding_map["iso-8859-3"] = ISO_8859_3;
+  encoding_map["iso-8859-4"] = ISO_8859_4;
+  encoding_map["iso-8859-5"] = ISO_8859_5;
+  encoding_map["iso-8859-6"] = ISO_8859_6;
+  encoding_map["iso-8859-7"] = ISO_8859_7;
+  encoding_map["iso-8859-8"] = ISO_8859_8;
+  encoding_map["iso-8859-8-i"] = ISO_8859_8_I;
+  encoding_map["iso-8859-9"] = ISO_8859_9;
+  encoding_map["iso-9959-1"] = ISO_8859_1;      // common typo
+  encoding_map["iso-ir-100"] = ISO_8859_1;
+  encoding_map["iso-ir-101"] = ISO_8859_2;
+  encoding_map["iso-ir-109"] = ISO_8859_3;
+  encoding_map["iso-ir-110"] = ISO_8859_4;
+  encoding_map["iso-ir-126"] = ISO_8859_7;
+  encoding_map["iso-ir-127"] = ISO_8859_6;
+  encoding_map["iso-ir-138"] = ISO_8859_8;
+  encoding_map["iso-ir-144"] = ISO_8859_5;
+  encoding_map["iso-ir-148"] = ISO_8859_9;
+  encoding_map["iso-ir-149"] = KOREAN_EUC_KR;
+  encoding_map["iso-ir-157"] = ISO_8859_10;
+  encoding_map["iso-ir-58"] = CHINESE_GB;
+  encoding_map["iso-latin-1"] = ISO_8859_1;
+  encoding_map["iso_2022-cn"] = ISO_2022_CN;
+  encoding_map["iso_2022-kr"] = ISO_2022_KR;
+  encoding_map["iso_8859-1"] = ISO_8859_1;
+  encoding_map["iso_8859-10:1992"] = ISO_8859_10;
+  encoding_map["iso_8859-11"] = ISO_8859_11;
+  encoding_map["iso_8859-13"] = ISO_8859_13;
+  encoding_map["iso_8859-15"] = ISO_8859_15;
+  encoding_map["iso_8859-1:1987"] = ISO_8859_1;
+  encoding_map["iso_8859-2"] = ISO_8859_2;
+  encoding_map["iso_8859-2:1987"] = ISO_8859_2;
+  encoding_map["iso_8859-3"] = ISO_8859_3;
+  encoding_map["iso_8859-3:1988"] = ISO_8859_3;
+  encoding_map["iso_8859-4"] = ISO_8859_4;
+  encoding_map["iso_8859-4:1988"] = ISO_8859_4;
+  encoding_map["iso_8859-5"] = ISO_8859_5;
+  encoding_map["iso_8859-5:1988"] = ISO_8859_5;
+  encoding_map["iso_8859-6"] = ISO_8859_6;
+  encoding_map["iso_8859-6:1987"] = ISO_8859_6;
+  encoding_map["iso_8859-7"] = ISO_8859_7;
+  encoding_map["iso_8859-7:1987"] = ISO_8859_7;
+  encoding_map["iso_8859-8"] = ISO_8859_8;
+  encoding_map["iso_8859-8:1988:"] = ISO_8859_8;
+  encoding_map["iso_8859-9"] = ISO_8859_9;
+  encoding_map["iso_8859-9:1989"] = ISO_8859_9;
+  encoding_map["jagran"] = JAGRAN;
+  encoding_map["jis"] = JAPANESE_JIS;  // not iana standard
+  encoding_map["koi8-cs"] = CZECH_CSN_369103;
+  encoding_map["koi8-r"] = RUSSIAN_KOI8_R;
+  encoding_map["koi8-ru"] = RUSSIAN_KOI8_RU;  // not iana standard
+  encoding_map["koi8-u"] = RUSSIAN_KOI8_RU;
+  encoding_map["koi8r"] = RUSSIAN_KOI8_R;  // not iana standard
+  encoding_map["koi8u"] = RUSSIAN_KOI8_RU;  // not iana standard
+  encoding_map["korean"] = KOREAN_EUC_KR;  // i assume this is what is meant
+  encoding_map["ks-c-5601"] = KOREAN_EUC_KR;  // not iana standard
+  encoding_map["ks-c-5601-1987"] = KOREAN_EUC_KR;  // not iana standard
+  encoding_map["ks_c_5601-1989"] = KOREAN_EUC_KR;
+  encoding_map["ksc"] = KOREAN_EUC_KR;  // not iana standard
+  encoding_map["l1"] = ISO_8859_1;
+  encoding_map["l2"] = ISO_8859_2;
+  encoding_map["l3"] = ISO_8859_3;
+  encoding_map["l4"] = ISO_8859_4;
+  encoding_map["l5"] = ISO_8859_9;
+  encoding_map["l6"] = ISO_8859_10;
+  encoding_map["latin-1"] = ISO_8859_1;         // not iana standard
+  encoding_map["latin1"] = ISO_8859_1;
+  encoding_map["latin2"] = ISO_8859_2;
+  encoding_map["latin3"] = ISO_8859_3;
+  encoding_map["latin4"] = ISO_8859_4;
+  encoding_map["latin5"] = ISO_8859_9;
+  encoding_map["latin6"] = ISO_8859_10;
+  encoding_map["mac"] = MACINTOSH_ROMAN;
+  encoding_map["macintosh"] = MACINTOSH_ROMAN;
+  encoding_map["macintosh-roman"] = MACINTOSH_ROMAN;
+  encoding_map["ms932"] = JAPANESE_CP932;  // not iana standard
+  encoding_map["ms_kanji"] = JAPANESE_CP932;
+  encoding_map["shift-jis"] = JAPANESE_SHIFT_JIS;
+  encoding_map["shift_jis"] = JAPANESE_SHIFT_JIS;
+  encoding_map["sjis"] = JAPANESE_SHIFT_JIS;  // not iana standard
+  encoding_map["sjs"] = JAPANESE_SHIFT_JIS;  // not iana standard
+  encoding_map["sun_eu_greek"] = ISO_8859_7;
+  encoding_map["tab"] = TAMIL_BI;
+  encoding_map["tam"] = TAMIL_MONO;
+  encoding_map["tis-620"] = ISO_8859_11;
+  encoding_map["tscii"] = TSCII;
+  encoding_map["un"] = UNKNOWN_ENCODING;  // not iana standard
+  encoding_map["unicode"] = UNICODE;  // not iana standard
+  encoding_map["unicode-1-1-utf-7"] = UTF7;
+  encoding_map["unicode-1-1-utf-8"] = UTF8;
+  encoding_map["unicode-2-0-utf-7"] = UTF7;
+  encoding_map["unknown"] = UNKNOWN_ENCODING;  // not iana standard
+  encoding_map["us"] = ISO_8859_1;
+  encoding_map["us-ascii"] = ISO_8859_1;
+  encoding_map["utf-16be"] = UTF16BE;
+  encoding_map["utf-16le"] = UTF16LE;
+  encoding_map["utf-32be"] = UTF32BE;
+  encoding_map["utf-32le"] = UTF32LE;
+  encoding_map["utf-7"] = UTF7;
+  encoding_map["utf-8"] = UTF8;
+  encoding_map["utf7"] = UTF7;
+  encoding_map["utf8"] = UTF8;  // not iana standard
+  encoding_map["visual"] = HEBREW_VISUAL;
+  encoding_map["win-1250"] = MSFT_CP1250;  // not iana standard
+  encoding_map["win-1251"] = RUSSIAN_CP1251;  // not iana standard
+  encoding_map["window-874"] = MSFT_CP874;
+  encoding_map["windows-1250"] = MSFT_CP1250;
+  encoding_map["windows-1251"] = RUSSIAN_CP1251;
+  encoding_map["windows-1252"] = MSFT_CP1252;
+  encoding_map["windows-1253"] = MSFT_CP1253;
+  encoding_map["windows-1254"] = MSFT_CP1254;
+  encoding_map["windows-1255"] = MSFT_CP1255;
+  encoding_map["windows-1256"] = MSFT_CP1256;
+  encoding_map["windows-1257"] = MSFT_CP1257;
+  encoding_map["windows-31j"] = JAPANESE_CP932;
+  encoding_map["windows-874"] = MSFT_CP874;
+  encoding_map["windows-936"] = GBK;
+  encoding_map["x-big5"] = CHINESE_BIG5;
+  encoding_map["x-binaryenc"] = BINARYENC;  // not iana standard
+  encoding_map["x-cp1250"] = MSFT_CP1250;
+  encoding_map["x-cp1251"] = RUSSIAN_CP1251;
+  encoding_map["x-cp1252"] = MSFT_CP1252;
+  encoding_map["x-cp1253"] = MSFT_CP1253;
+  encoding_map["x-cp1254"] = MSFT_CP1254;
+  encoding_map["x-cp1255"] = MSFT_CP1255;
+  encoding_map["x-cp1256"] = MSFT_CP1256;
+  encoding_map["x-cp1257"] = MSFT_CP1257;
+  encoding_map["x-euc-jp"] = JAPANESE_EUC_JP;
+  encoding_map["x-euc-tw"] = CHINESE_CNS;
+  encoding_map["x-gbk"] = GBK;
+  encoding_map["x-iso-10646-ucs-2-be"] = UTF16BE;
+  encoding_map["x-iso-10646-ucs-2-le"] = UTF16LE;
+  encoding_map["x-iso-10646-ucs-4-be"] = UTF32BE;
+  encoding_map["x-iso-10646-ucs-4-le"] = UTF32LE;
+  encoding_map["x-jis"] = JAPANESE_JIS;  // not iana standard
+  encoding_map["x-mac-roman"] = MACINTOSH_ROMAN;
+  encoding_map["x-shift_jis"] = JAPANESE_SHIFT_JIS;  // not iana standard
+  encoding_map["x-sjis"] = JAPANESE_SHIFT_JIS;
+  encoding_map["x-unicode-2-0-utf-7"] = UTF7;
+  encoding_map["x-utf8utf8"] = UTF8UTF8;  // not iana standard
+  encoding_map["x-x-big5"] = CHINESE_BIG5;
+  encoding_map["zh_cn.euc"] = CHINESE_GB;
+  encoding_map["zh_tw-big5"] = CHINESE_BIG5;
+  encoding_map["zh_tw-euc"] = CHINESE_CNS;
+
+  // Remove they entry for the empty string, if any.
+  encoding_map.erase("");
+}
+
+REGISTER_MODULE_INITIALIZER(encodings, {
+    InitEncodings();
+});
+
+// ----------------------------------------------------------------------
+// EncodingNameAliasToEncoding()
+//
+// This function takes an encoding name/alias and returns the Encoding
+// enum. The input is case insensitive. It is the union of the common
+// IANA standard names, the charset names used in Netscape Navigator,
+// and some common names we have been using.
+// See: http://www.iana.org/assignments/character-sets
+// http://physics.hallym.ac.kr/resource/relnotes/windows-2.0.html
+//
+// UNKNOWN_ENCODING is returned if none matches.
+//
+// TODO: Check if it is possible to remove the non-standard,
+// non-netscape-use names. It is because this routine is used for
+// encoding detections from html meta info. Non-standard names may
+// introduce noise on encoding detection.
+//
+// TODO: Unify EncodingNameAliasToEncoding and EncodingFromName,
+// or determine why such a unification is not possible.
+// ----------------------------------------------------------------------
+Encoding EncodingNameAliasToEncoding(const char *encoding_name) {
+  if (!encoding_name) {
+    return UNKNOWN_ENCODING;
+  }
+
+  // The map is initialized during InitGoogle() in a thread-safe manner.
+  CHECK(!encoding_map.empty()) << ": Must call InitGoogle()";
+
+  EncodingMap::iterator emi = encoding_map.find(encoding_name);
+  if (emi != encoding_map.end()) {
+    return emi->second;
+  } else {
+    return UNKNOWN_ENCODING;
+  }
+}
+#endif
+
+const char* default_encoding_name() {
+  return kEncodingInfoTable[LATIN1].encoding_name_;
+}
+
+static const char* const kInvalidEncodingName = "invalid_encoding";
+
+const char *invalid_encoding_name() {
+  return kInvalidEncodingName;
+}
+
+
+
+// *************************************************************
+// Miscellany
+// *************************************************************
+
+
+Encoding PreferredWebOutputEncoding(Encoding enc) {
+  return IsValidEncoding(enc)
+      ? kEncodingInfoTable[enc].preferred_web_output_encoding_
+      : UTF8;
+}