1 /*
2 * Copyright (C) 2011 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16 #ifndef __IO_STREAM_H__
17 #define __IO_STREAM_H__
18 
19 #include <stdlib.h>
20 #include <stdio.h>
21 
22 #include "ErrorLog.h"
23 
24 class IOStream {
25 public:
26 
IOStream(size_t bufSize)27     IOStream(size_t bufSize) {
28         m_iostreamBuf = NULL;
29         m_bufsize = bufSize;
30         m_free = 0;
31     }
32 
idealAllocSize(size_t len)33     virtual size_t idealAllocSize(size_t len) {
34         return m_bufsize < len ? len : m_bufsize;
35     }
36 
37     virtual void *allocBuffer(size_t minSize) = 0;
38     virtual int commitBuffer(size_t size) = 0;
39     virtual const unsigned char *readFully( void *buf, size_t len) = 0;
40     virtual const unsigned char *commitBufferAndReadFully(size_t size, void *buf, size_t len) = 0;
41     virtual const unsigned char *read( void *buf, size_t *inout_len) = 0;
42     virtual int writeFully(const void* buf, size_t len) = 0;
43 
~IOStream()44     virtual ~IOStream() {
45 
46         // NOTE: m_iostreamBuf is 'owned' by the child class thus we expect it to be released by it
47     }
48 
alloc(size_t len)49     virtual unsigned char *alloc(size_t len) {
50 
51         if (m_iostreamBuf && len > m_free) {
52             if (flush() < 0) {
53                 ERR("Failed to flush in alloc\n");
54                 return NULL; // we failed to flush so something is wrong
55             }
56         }
57 
58         if (!m_iostreamBuf || len > m_bufsize) {
59             int allocLen = this->idealAllocSize(len);
60             m_iostreamBuf = (unsigned char *)allocBuffer(allocLen);
61             if (!m_iostreamBuf) {
62                 ERR("Alloc (%u bytes) failed\n", allocLen);
63                 return NULL;
64             }
65             m_bufsize = m_free = allocLen;
66         }
67 
68         unsigned char *ptr;
69 
70         ptr = m_iostreamBuf + (m_bufsize - m_free);
71         m_free -= len;
72 
73         return ptr;
74     }
75 
flush()76     virtual int flush() {
77 
78         if (!m_iostreamBuf || m_free == m_bufsize) return 0;
79 
80         int stat = commitBuffer(m_bufsize - m_free);
81         m_iostreamBuf = NULL;
82         m_free = 0;
83         return stat;
84     }
85 
readback(void * buf,size_t len)86     const unsigned char *readback(void *buf, size_t len) {
87         if (m_iostreamBuf && m_free != m_bufsize) {
88             size_t size = m_bufsize - m_free;
89             m_iostreamBuf = NULL;
90             m_free = 0;
91             return commitBufferAndReadFully(size, buf, len);
92         }
93         return readFully(buf, len);
94     }
95 
96     // These two methods are defined and used in GLESv2_enc. Any reference
97     // outside of GLESv2_enc will produce a link error. This is intentional
98     // (technical debt).
99     void readbackPixels(void* context, int width, int height, unsigned int format, unsigned int type, void* pixels);
100     void uploadPixels(void* context, int width, int height, int depth, unsigned int format, unsigned int type, const void* pixels);
101 
102 
103 private:
104     unsigned char *m_iostreamBuf;
105     size_t m_bufsize;
106     size_t m_free;
107 };
108 
109 //
110 // When a client opens a connection to the renderer, it should
111 // send unsigned int value indicating the "clientFlags".
112 // The following are the bitmask of the clientFlags.
113 // currently only one bit is used which flags the server
114 // it should exit.
115 //
116 #define IOSTREAM_CLIENT_EXIT_SERVER      1
117 
118 #endif
119