| /****************************************************************************** |
| * |
| * Copyright (C) 2014 Google, Inc. |
| * |
| * 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. |
| * |
| ******************************************************************************/ |
| |
| #pragma once |
| |
| #include <stdbool.h> |
| #include <stddef.h> |
| |
| #ifdef __cplusplus |
| extern "C" { |
| #endif |
| |
| typedef struct buffer_t buffer_t; |
| |
| // Returns a new buffer of |size| bytes. Returns NULL if a buffer could not be |
| // allocated. |size| must be non-zero. The caller must release this buffer with |
| // |buffer_free|. |
| buffer_t* buffer_new(size_t size); |
| |
| // Creates a new reference to the buffer |buf|. A reference is indistinguishable |
| // from the original: writes to the original will be reflected in the reference |
| // and vice versa. In other words, this function creates an alias to |buf|. The |
| // caller must release the returned buffer with |buffer_free|. Note that |
| // releasing |
| // the returned buffer does not release |buf|. |buf| must not be NULL. |
| buffer_t* buffer_new_ref(const buffer_t* buf); |
| |
| // Creates a new reference to the last |slice_size| bytes of |buf|. See |
| // |buffer_new_ref| for a description of references. |slice_size| must be |
| // greater than 0 and may be at most |buffer_length| |
| // (0 < slice_size <= buffer_length). |buf| must not be NULL. |
| buffer_t* buffer_new_slice(const buffer_t* buf, size_t slice_size); |
| |
| // Frees a buffer object. |buf| may be NULL. |
| void buffer_free(buffer_t* buf); |
| |
| // Returns a pointer to a writeable memory region for |buf|. All references |
| // and slices that share overlapping bytes will also be written to when |
| // writing to the returned pointer. The caller may safely write up to |
| // |buffer_length| consecutive bytes starting at the address returned by |
| // this function. |buf| must not be NULL. |
| void* buffer_ptr(const buffer_t* buf); |
| |
| // Returns the length of the writeable memory region referred to by |buf|. |
| // |buf| must not be NULL. |
| size_t buffer_length(const buffer_t* buf); |
| |
| #ifdef __cplusplus |
| } |
| #endif |