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_buf = NULL; 29 m_bufsize = bufSize; 30 m_free = 0; 31 } 32 33 virtual void *allocBuffer(size_t minSize) = 0; 34 virtual int commitBuffer(size_t size) = 0; 35 virtual const unsigned char *readFully( void *buf, size_t len) = 0; 36 virtual const unsigned char *read( void *buf, size_t *inout_len) = 0; 37 virtual int writeFully(const void* buf, size_t len) = 0; 38 ~IOStream()39 virtual ~IOStream() { 40 41 // NOTE: m_buf is 'owned' by the child class thus we expect it to be released by it 42 } 43 alloc(size_t len)44 unsigned char *alloc(size_t len) { 45 46 if (m_buf && len > m_free) { 47 if (flush() < 0) { 48 ERR("Failed to flush in alloc\n"); 49 return NULL; // we failed to flush so something is wrong 50 } 51 } 52 53 if (!m_buf || len > m_bufsize) { 54 int allocLen = m_bufsize < len ? len : m_bufsize; 55 m_buf = (unsigned char *)allocBuffer(allocLen); 56 if (!m_buf) { 57 ERR("Alloc (%u bytes) failed\n", allocLen); 58 return NULL; 59 } 60 m_bufsize = m_free = allocLen; 61 } 62 63 unsigned char *ptr; 64 65 ptr = m_buf + (m_bufsize - m_free); 66 m_free -= len; 67 68 return ptr; 69 } 70 flush()71 int flush() { 72 73 if (!m_buf || m_free == m_bufsize) return 0; 74 75 int stat = commitBuffer(m_bufsize - m_free); 76 m_buf = NULL; 77 m_free = 0; 78 return stat; 79 } 80 readback(void * buf,size_t len)81 const unsigned char *readback(void *buf, size_t len) { 82 flush(); 83 return readFully(buf, len); 84 } 85 86 87 private: 88 unsigned char *m_buf; 89 size_t m_bufsize; 90 size_t m_free; 91 }; 92 93 // 94 // When a client opens a connection to the renderer, it should 95 // send unsigned int value indicating the "clientFlags". 96 // The following are the bitmask of the clientFlags. 97 // currently only one bit is used which flags the server 98 // it should exit. 99 // 100 #define IOSTREAM_CLIENT_EXIT_SERVER 1 101 102 #endif 103