The Android Open Source Project | dd7bc33 | 2009-03-03 19:32:55 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2007 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 | |
| 17 | #define LOG_TAG "buffer" |
| 18 | |
| 19 | #include <assert.h> |
| 20 | #include <errno.h> |
| 21 | #include <stdlib.h> |
| 22 | #include <unistd.h> |
| 23 | |
| 24 | #include "buffer.h" |
| 25 | #include "loghack.h" |
| 26 | |
| 27 | Buffer* bufferCreate(size_t capacity) { |
| 28 | Buffer* buffer = malloc(sizeof(Buffer)); |
| 29 | if (buffer == NULL) { |
| 30 | return NULL; |
| 31 | } |
| 32 | buffer->capacity = capacity; |
| 33 | buffer->expected = 0; |
| 34 | buffer->data = malloc(capacity); |
| 35 | if (buffer->data == NULL) { |
| 36 | free(buffer); |
| 37 | return NULL; |
| 38 | } |
| 39 | return buffer; |
| 40 | } |
| 41 | |
| 42 | void bufferFree(Buffer* buffer) { |
| 43 | free(buffer->data); |
| 44 | free(buffer); |
| 45 | } |
| 46 | |
| 47 | Buffer* bufferWrap(char* data, size_t capacity, size_t size) { |
| 48 | Buffer* buffer = malloc(sizeof(Buffer)); |
| 49 | if (buffer == NULL) { |
| 50 | return NULL; |
| 51 | } |
| 52 | |
| 53 | buffer->data = data; |
| 54 | buffer->capacity = capacity; |
| 55 | buffer->size = size; |
| 56 | buffer->expected = 0; |
| 57 | return buffer; |
| 58 | } |
| 59 | |
| 60 | int bufferPrepareForRead(Buffer* buffer, size_t expected) { |
| 61 | if (expected > buffer->capacity) { |
| 62 | // Expand buffer. |
| 63 | char* expanded = realloc(buffer->data, expected); |
| 64 | if (expanded == NULL) { |
| 65 | errno = ENOMEM; |
| 66 | return -1; |
| 67 | } |
| 68 | buffer->capacity = expected; |
| 69 | buffer->data = expanded; |
| 70 | } |
| 71 | |
| 72 | buffer->size = 0; |
| 73 | buffer->expected = expected; |
| 74 | return 0; |
| 75 | } |
| 76 | |
| 77 | ssize_t bufferRead(Buffer* buffer, int fd) { |
| 78 | assert(buffer->size < buffer->expected); |
| 79 | |
| 80 | ssize_t bytesRead = read(fd, |
| 81 | buffer->data + buffer->size, |
| 82 | buffer->expected - buffer->size); |
| 83 | |
| 84 | if (bytesRead > 0) { |
| 85 | buffer->size += bytesRead; |
| 86 | return buffer->size; |
| 87 | } |
| 88 | |
| 89 | return bytesRead; |
| 90 | } |
| 91 | |
| 92 | void bufferPrepareForWrite(Buffer* buffer) { |
| 93 | buffer->remaining = buffer->size; |
| 94 | } |
| 95 | |
| 96 | ssize_t bufferWrite(Buffer* buffer, int fd) { |
| 97 | assert(buffer->remaining > 0); |
| 98 | assert(buffer->remaining <= buffer->size); |
| 99 | |
| 100 | ssize_t bytesWritten = write(fd, |
| 101 | buffer->data + buffer->size - buffer->remaining, |
| 102 | buffer->remaining); |
| 103 | |
| 104 | if (bytesWritten >= 0) { |
| 105 | buffer->remaining -= bytesWritten; |
| 106 | |
Steve Block | 9786ec4 | 2011-12-20 16:07:45 +0000 | [diff] [blame] | 107 | ALOGD("Buffer bytes written: %d", (int) bytesWritten); |
| 108 | ALOGD("Buffer size: %d", (int) buffer->size); |
| 109 | ALOGD("Buffer remaining: %d", (int) buffer->remaining); |
The Android Open Source Project | dd7bc33 | 2009-03-03 19:32:55 -0800 | [diff] [blame] | 110 | |
| 111 | return buffer->remaining; |
| 112 | } |
| 113 | |
| 114 | return bytesWritten; |
| 115 | } |
| 116 | |