1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
|
<?php
namespace GuzzleHttp\Psr7;
use Psr\Http\Message\StreamInterface;
/**
* Reads from multiple streams, one after the other.
*
* This is a read-only stream decorator.
*/
class AppendStream implements StreamInterface
{
/** @var StreamInterface[] Streams being decorated */
private $streams = [];
private $seekable = true;
private $current = 0;
private $pos = 0;
/**
* @param StreamInterface[] $streams Streams to decorate. Each stream must
* be readable.
*/
public function __construct(array $streams = [])
{
foreach ($streams as $stream) {
$this->addStream($stream);
}
}
public function __toString()
{
try {
$this->rewind();
return $this->getContents();
} catch (\Exception $e) {
return '';
}
}
/**
* Add a stream to the AppendStream
*
* @param StreamInterface $stream Stream to append. Must be readable.
*
* @throws \InvalidArgumentException if the stream is not readable
*/
public function addStream(StreamInterface $stream)
{
if (!$stream->isReadable()) {
throw new \InvalidArgumentException('Each stream must be readable');
}
// The stream is only seekable if all streams are seekable
if (!$stream->isSeekable()) {
$this->seekable = false;
}
$this->streams[] = $stream;
}
public function getContents()
{
return copy_to_string($this);
}
/**
* Closes each attached stream.
*
* {@inheritdoc}
*/
public function close()
{
$this->pos = $this->current = 0;
$this->seekable = true;
foreach ($this->streams as $stream) {
$stream->close();
}
$this->streams = [];
}
/**
* Detaches each attached stream.
*
* Returns null as it's not clear which underlying stream resource to return.
*
* {@inheritdoc}
*/
public function detach()
{
$this->pos = $this->current = 0;
$this->seekable = true;
foreach ($this->streams as $stream) {
$stream->detach();
}
$this->streams = [];
}
public function tell()
{
return $this->pos;
}
/**
* Tries to calculate the size by adding the size of each stream.
*
* If any of the streams do not return a valid number, then the size of the
* append stream cannot be determined and null is returned.
*
* {@inheritdoc}
*/
public function getSize()
{
$size = 0;
foreach ($this->streams as $stream) {
$s = $stream->getSize();
if ($s === null) {
return null;
}
$size += $s;
}
return $size;
}
public function eof()
{
return !$this->streams ||
($this->current >= count($this->streams) - 1 &&
$this->streams[$this->current]->eof());
}
public function rewind()
{
$this->seek(0);
}
/**
* Attempts to seek to the given position. Only supports SEEK_SET.
*
* {@inheritdoc}
*/
public function seek($offset, $whence = SEEK_SET)
{
if (!$this->seekable) {
throw new \RuntimeException('This AppendStream is not seekable');
} elseif ($whence !== SEEK_SET) {
throw new \RuntimeException('The AppendStream can only seek with SEEK_SET');
}
$this->pos = $this->current = 0;
// Rewind each stream
foreach ($this->streams as $i => $stream) {
try {
$stream->rewind();
} catch (\Exception $e) {
throw new \RuntimeException('Unable to seek stream '
. $i . ' of the AppendStream', 0, $e);
}
}
// Seek to the actual position by reading from each stream
while ($this->pos < $offset && !$this->eof()) {
$result = $this->read(min(8096, $offset - $this->pos));
if ($result === '') {
break;
}
}
}
/**
* Reads from all of the appended streams until the length is met or EOF.
*
* {@inheritdoc}
*/
public function read($length)
{
$buffer = '';
$total = count($this->streams) - 1;
$remaining = $length;
$progressToNext = false;
while ($remaining > 0) {
// Progress to the next stream if needed.
if ($progressToNext || $this->streams[$this->current]->eof()) {
$progressToNext = false;
if ($this->current === $total) {
break;
}
$this->current++;
}
$result = $this->streams[$this->current]->read($remaining);
// Using a loose comparison here to match on '', false, and null
if ($result == null) {
$progressToNext = true;
continue;
}
$buffer .= $result;
$remaining = $length - strlen($buffer);
}
$this->pos += strlen($buffer);
return $buffer;
}
public function isReadable()
{
return true;
}
public function isWritable()
{
return false;
}
public function isSeekable()
{
return $this->seekable;
}
public function write($string)
{
throw new \RuntimeException('Cannot write to an AppendStream');
}
public function getMetadata($key = null)
{
return $key ? null : [];
}
}
|