1
2/*
3 * Copyright 2006 The Android Open Source Project
4 *
5 * Use of this source code is governed by a BSD-style license that can be
6 * found in the LICENSE file.
7 */
8
9
10#include "SkXMLParser.h"
11#include "SkChunkAlloc.h"
12#include "SkString.h"
13#include "SkStream.h"
14
15#include "expat.h"
16
17static inline char* dupstr(SkChunkAlloc& chunk, const char src[], size_t len)
18{
19    SkASSERT(src);
20    char*   dst = (char*)chunk.alloc(len + 1, SkChunkAlloc::kThrow_AllocFailType);
21
22    memcpy(dst, src, len);
23    dst[len] = 0;
24    return dst;
25}
26
27static inline int count_pairs(const char** p)
28{
29    const char** start = p;
30    while (*p)
31    {
32        SkASSERT(p[1] != NULL);
33        p += 2;
34    }
35    return (p - start) >> 1;
36}
37
38struct Data {
39    Data() : fAlloc(2048), fState(NORMAL) {}
40
41    XML_Parser              fParser;
42    SkXMLPullParser::Curr*  fCurr;
43    SkChunkAlloc            fAlloc;
44
45    enum State {
46        NORMAL,
47        MISSED_START_TAG,
48        RETURN_END_TAG
49    };
50    State fState;
51    const char* fEndTag;    // if state is RETURN_END_TAG
52};
53
54static void XMLCALL start_proc(void *data, const char *el, const char **attr)
55{
56    Data*                   p = (Data*)data;
57    SkXMLPullParser::Curr*  c = p->fCurr;
58    SkChunkAlloc&           alloc = p->fAlloc;
59
60    c->fName = dupstr(alloc, el, strlen(el));
61
62    int n = count_pairs(attr);
63    SkXMLPullParser::AttrInfo* info = (SkXMLPullParser::AttrInfo*)alloc.alloc(n * sizeof(SkXMLPullParser::AttrInfo),
64                                                                              SkChunkAlloc::kThrow_AllocFailType);
65    c->fAttrInfoCount = n;
66    c->fAttrInfos = info;
67
68    for (int i = 0; i < n; i++)
69    {
70        info[i].fName = dupstr(alloc, attr[0], strlen(attr[0]));
71        info[i].fValue = dupstr(alloc, attr[1], strlen(attr[1]));
72        attr += 2;
73    }
74
75    c->fEventType = SkXMLPullParser::START_TAG;
76    XML_StopParser(p->fParser, true);
77}
78
79static void XMLCALL end_proc(void *data, const char *el)
80{
81    Data*                   p = (Data*)data;
82    SkXMLPullParser::Curr*  c = p->fCurr;
83
84    if (c->fEventType == SkXMLPullParser::START_TAG)
85    {
86        /*  if we get here, we were called with a start_tag immediately
87            followed by this end_tag. The caller will only see the end_tag,
88            so we set a flag to notify them of the missed start_tag
89        */
90        p->fState = Data::MISSED_START_TAG;
91
92        SkASSERT(c->fName != NULL);
93        SkASSERT(strcmp(c->fName, el) == 0);
94    }
95    else
96        c->fName = dupstr(p->fAlloc, el, strlen(el));
97
98    c->fEventType = SkXMLPullParser::END_TAG;
99    XML_StopParser(p->fParser, true);
100}
101
102#include <ctype.h>
103
104static bool isws(const char s[])
105{
106    for (; *s; s++)
107        if (!isspace(*s))
108            return false;
109    return true;
110}
111
112static void XMLCALL text_proc(void* data, const char* text, int len)
113{
114    Data*                   p = (Data*)data;
115    SkXMLPullParser::Curr*  c = p->fCurr;
116
117    c->fName = dupstr(p->fAlloc, text, len);
118    c->fIsWhitespace = isws(c->fName);
119
120    c->fEventType = SkXMLPullParser::TEXT;
121    XML_StopParser(p->fParser, true);
122}
123
124//////////////////////////////////////////////////////////////////////////
125
126struct SkXMLPullParser::Impl {
127    Data    fData;
128    void*   fBuffer;
129    size_t  fBufferLen;
130};
131
132static void reportError(XML_Parser parser)
133{
134    XML_Error code = XML_GetErrorCode(parser);
135    int lineNumber = XML_GetCurrentLineNumber(parser);
136    const char* msg = XML_ErrorString(code);
137
138    printf("-------- XML error [%d] on line %d, %s\n", code, lineNumber, msg);
139}
140
141bool SkXMLPullParser::onInit()
142{
143    fImpl = new Impl;
144
145    XML_Parser p = XML_ParserCreate(NULL);
146    SkASSERT(p);
147
148    fImpl->fData.fParser = p;
149    fImpl->fData.fCurr = &fCurr;
150
151    XML_SetElementHandler(p, start_proc, end_proc);
152    XML_SetCharacterDataHandler(p, text_proc);
153    XML_SetUserData(p, &fImpl->fData);
154
155    size_t len = fStream->read(NULL, 0);
156    fImpl->fBufferLen = len;
157    fImpl->fBuffer = sk_malloc_throw(len);
158    fStream->rewind();
159    size_t  len2 = fStream->read(fImpl->fBuffer, len);
160    return len2 == len;
161}
162
163void SkXMLPullParser::onExit()
164{
165    sk_free(fImpl->fBuffer);
166    XML_ParserFree(fImpl->fData.fParser);
167    delete fImpl;
168    fImpl = NULL;
169}
170
171SkXMLPullParser::EventType SkXMLPullParser::onNextToken()
172{
173    if (Data::RETURN_END_TAG == fImpl->fData.fState)
174    {
175        fImpl->fData.fState = Data::NORMAL;
176        fCurr.fName = fImpl->fData.fEndTag; // restore name from (below) save
177        return SkXMLPullParser::END_TAG;
178    }
179
180    fImpl->fData.fAlloc.reuse();
181
182    XML_Parser p = fImpl->fData.fParser;
183    XML_Status status;
184
185    status = XML_ResumeParser(p);
186
187CHECK_STATUS:
188    switch (status) {
189    case XML_STATUS_OK:
190        return SkXMLPullParser::END_DOCUMENT;
191
192    case XML_STATUS_ERROR:
193        if (XML_GetErrorCode(p) != XML_ERROR_NOT_SUSPENDED)
194        {
195            reportError(p);
196            return SkXMLPullParser::ERROR;
197        }
198        status = XML_Parse(p, (const char*)fImpl->fBuffer, fImpl->fBufferLen, true);
199        goto CHECK_STATUS;
200
201    case XML_STATUS_SUSPENDED:
202        if (Data::MISSED_START_TAG == fImpl->fData.fState)
203        {
204            // return a start_tag, and clear the flag so we return end_tag next
205            SkASSERT(SkXMLPullParser::END_TAG == fCurr.fEventType);
206            fImpl->fData.fState = Data::RETURN_END_TAG;
207            fImpl->fData.fEndTag = fCurr.fName;  // save this pointer
208            return SkXMLPullParser::START_TAG;
209        }
210        break;
211    }
212    return fCurr.fEventType;
213}
214
215