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/*
* Copyright (C) 2007 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.
*/
#define LOG_TAG "buffer"
#include <assert.h>
#include <errno.h>
#include <stdlib.h>
#include <unistd.h>
#include "buffer.h"
#include "loghack.h"
Buffer* bufferCreate(size_t capacity) {
Buffer* buffer = malloc(sizeof(Buffer));
if (buffer == NULL) {
return NULL;
}
buffer->capacity = capacity;
buffer->expected = 0;
buffer->data = malloc(capacity);
if (buffer->data == NULL) {
free(buffer);
return NULL;
}
return buffer;
}
void bufferFree(Buffer* buffer) {
free(buffer->data);
free(buffer);
}
Buffer* bufferWrap(char* data, size_t capacity, size_t size) {
Buffer* buffer = malloc(sizeof(Buffer));
if (buffer == NULL) {
return NULL;
}
buffer->data = data;
buffer->capacity = capacity;
buffer->size = size;
buffer->expected = 0;
return buffer;
}
int bufferPrepareForRead(Buffer* buffer, size_t expected) {
if (expected > buffer->capacity) {
// Expand buffer.
char* expanded = realloc(buffer->data, expected);
if (expanded == NULL) {
errno = ENOMEM;
return -1;
}
buffer->capacity = expected;
buffer->data = expanded;
}
buffer->size = 0;
buffer->expected = expected;
return 0;
}
ssize_t bufferRead(Buffer* buffer, int fd) {
assert(buffer->size < buffer->expected);
ssize_t bytesRead = read(fd,
buffer->data + buffer->size,
buffer->expected - buffer->size);
if (bytesRead > 0) {
buffer->size += bytesRead;
return buffer->size;
}
return bytesRead;
}
void bufferPrepareForWrite(Buffer* buffer) {
buffer->remaining = buffer->size;
}
ssize_t bufferWrite(Buffer* buffer, int fd) {
assert(buffer->remaining > 0);
assert(buffer->remaining <= buffer->size);
ssize_t bytesWritten = write(fd,
buffer->data + buffer->size - buffer->remaining,
buffer->remaining);
if (bytesWritten >= 0) {
buffer->remaining -= bytesWritten;
LOGD("Buffer bytes written: %d", (int) bytesWritten);
LOGD("Buffer size: %d", (int) buffer->size);
LOGD("Buffer remaining: %d", (int) buffer->remaining);
return buffer->remaining;
}
return bytesWritten;
}
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