1 files changed, 116 insertions, 0 deletions
diff --git a/libcutils/buffer.c b/libcutils/buffer.c
new file mode 100644
index 000000000..f34b8f892
--- /dev/null
+++ b/libcutils/buffer.c
@@ -0,0 +1,116 @@
+/*
+ * 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;
+}
+