1/*
2 * Copyright (C) 2007, 2008 Apple, Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include "config.h"
27#include "wtf/text/TextCodecUserDefined.h"
28
29#include "wtf/PassOwnPtr.h"
30#include "wtf/text/CString.h"
31#include "wtf/text/StringBuffer.h"
32#include "wtf/text/StringBuilder.h"
33#include "wtf/text/WTFString.h"
34
35namespace WTF {
36
37void TextCodecUserDefined::registerEncodingNames(EncodingNameRegistrar registrar)
38{
39    registrar("x-user-defined", "x-user-defined");
40}
41
42static PassOwnPtr<TextCodec> newStreamingTextDecoderUserDefined(const TextEncoding&, const void*)
43{
44    return adoptPtr(new TextCodecUserDefined);
45}
46
47void TextCodecUserDefined::registerCodecs(TextCodecRegistrar registrar)
48{
49    registrar("x-user-defined", newStreamingTextDecoderUserDefined, 0);
50}
51
52String TextCodecUserDefined::decode(const char* bytes, size_t length, FlushBehavior, bool, bool&)
53{
54    StringBuilder result;
55    result.reserveCapacity(length);
56
57    for (size_t i = 0; i < length; ++i) {
58        signed char c = bytes[i];
59        result.append(static_cast<UChar>(c & 0xF7FF));
60    }
61
62    return result.toString();
63}
64
65template<typename CharType>
66static CString encodeComplexUserDefined(const CharType* characters, size_t length, UnencodableHandling handling)
67{
68    Vector<char> result(length);
69    char* bytes = result.data();
70
71    size_t resultLength = 0;
72    for (size_t i = 0; i < length; ) {
73        UChar32 c;
74        U16_NEXT(characters, i, length, c);
75        signed char signedByte = c;
76        if ((signedByte & 0xF7FF) == c)
77            bytes[resultLength++] = signedByte;
78        else {
79            // No way to encode this character with x-user-defined.
80            UnencodableReplacementArray replacement;
81            int replacementLength = TextCodec::getUnencodableReplacement(c, handling, replacement);
82            result.grow(resultLength + replacementLength + length - i);
83            bytes = result.data();
84            memcpy(bytes + resultLength, replacement, replacementLength);
85            resultLength += replacementLength;
86        }
87    }
88
89    return CString(bytes, resultLength);
90}
91
92template<typename CharType>
93CString TextCodecUserDefined::encodeCommon(const CharType* characters, size_t length, UnencodableHandling handling)
94{
95    char* bytes;
96    CString result = CString::newUninitialized(length, bytes);
97
98    // Convert the string a fast way and simultaneously do an efficient check to see if it's all ASCII.
99    UChar ored = 0;
100    for (size_t i = 0; i < length; ++i) {
101        UChar c = characters[i];
102        bytes[i] = c;
103        ored |= c;
104    }
105
106    if (!(ored & 0xFF80))
107        return result;
108
109    // If it wasn't all ASCII, call the function that handles more-complex cases.
110    return encodeComplexUserDefined(characters, length, handling);
111}
112
113CString TextCodecUserDefined::encode(const UChar* characters, size_t length, UnencodableHandling handling)
114{
115    return encodeCommon(characters, length, handling);
116}
117
118CString TextCodecUserDefined::encode(const LChar* characters, size_t length, UnencodableHandling handling)
119{
120    return encodeCommon(characters, length, handling);
121}
122
123} // namespace WTF
124