blob: 46b8c6aaccf6592c4f00c825fc8fe32ad08908f3 (
plain)
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
|
/*
* Copyright (C) 2011 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#pragma once
#include "ErrorLog.h"
#include <assert.h>
#include <stdlib.h>
#include <stdio.h>
class IOStream {
protected:
explicit IOStream(size_t bufSize) : m_bufsize(bufSize) {}
~IOStream() {
// NOTE: m_buf was owned by the child class thus we expect it to be
// released and flushed before the object destruction.
assert(!m_buf || m_free == m_bufsize);
}
public:
size_t read(void* buf, size_t bufLen) {
if (!readRaw(buf, &bufLen)) {
return 0;
}
return bufLen;
}
unsigned char* alloc(size_t len) {
if (m_buf && len > m_free) {
if (flush() < 0) {
ERR("Failed to flush in alloc\n");
return NULL; // we failed to flush so something is wrong
}
}
if (!m_buf || len > m_bufsize) {
int allocLen = m_bufsize < len ? len : m_bufsize;
m_buf = (unsigned char *)allocBuffer(allocLen);
if (!m_buf) {
ERR("Alloc (%u bytes) failed\n", allocLen);
return NULL;
}
m_bufsize = m_free = allocLen;
}
unsigned char* ptr = m_buf + (m_bufsize - m_free);
m_free -= len;
return ptr;
}
int flush() {
if (!m_buf || m_free == m_bufsize) return 0;
int stat = commitBuffer(m_bufsize - m_free);
m_buf = NULL;
m_free = 0;
return stat;
}
protected:
virtual void *allocBuffer(size_t minSize) = 0;
virtual int commitBuffer(size_t size) = 0;
virtual const unsigned char *readRaw(void *buf, size_t *inout_len) = 0;
private:
unsigned char* m_buf = nullptr;
size_t m_bufsize;
size_t m_free = 0;
};
|
