1/*
2 * Copyright 2011 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8#include "SkReader32.h"
9#include "SkString.h"
10#include "SkWriter32.h"
11
12/*
13 *  Strings are stored as: length[4-bytes] + string_data + '\0' + pad_to_mul_4
14 */
15
16const char* SkReader32::readString(size_t* outLen) {
17    size_t len = this->readU32();
18    const void* ptr = this->peek();
19
20    // skip over the string + '\0' and then pad to a multiple of 4
21    size_t alignedSize = SkAlign4(len + 1);
22    this->skip(alignedSize);
23
24    if (outLen) {
25        *outLen = len;
26    }
27    return (const char*)ptr;
28}
29
30size_t SkReader32::readIntoString(SkString* copy) {
31    size_t len;
32    const char* ptr = this->readString(&len);
33    if (copy) {
34        copy->set(ptr, len);
35    }
36    return len;
37}
38
39void SkWriter32::writeString(const char str[], size_t len) {
40    if (NULL == str) {
41        str = "";
42        len = 0;
43    }
44    if ((long)len < 0) {
45        len = strlen(str);
46    }
47
48    // [ 4 byte len ] [ str ... ] [1 - 4 \0s]
49    uint32_t* ptr = this->reservePad(sizeof(uint32_t) + len + 1);
50    *ptr = SkToU32(len);
51    char* chars = (char*)(ptr + 1);
52    memcpy(chars, str, len);
53    chars[len] = '\0';
54}
55
56size_t SkWriter32::WriteStringSize(const char* str, size_t len) {
57    if ((long)len < 0) {
58        SkASSERT(str);
59        len = strlen(str);
60    }
61    const size_t lenBytes = 4;    // we use 4 bytes to record the length
62    // add 1 since we also write a terminating 0
63    return SkAlign4(lenBytes + len + 1);
64}
65
66void SkWriter32::growToAtLeast(size_t size) {
67    const bool wasExternal = (fExternal != NULL) && (fData == fExternal);
68
69    fCapacity = 4096 + SkTMax(size, fCapacity + (fCapacity / 2));
70    fInternal.realloc(fCapacity);
71    fData = fInternal.get();
72
73    if (wasExternal) {
74        // we were external, so copy in the data
75        memcpy(fData, fExternal, fUsed);
76    }
77}
78
79SkData* SkWriter32::snapshotAsData() const {
80    return SkData::NewWithCopy(fData, fUsed);
81}
82