Input.h revision e507721000647a7d8afe44c63ef7fd04ef8971b1
1/* 2 * Copyright 2014 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#ifndef IMG_UTILS_INPUT_H 18#define IMG_UTILS_INPUT_H 19 20#include <cutils/compiler.h> 21#include <utils/Errors.h> 22#include <stdint.h> 23 24namespace android { 25namespace img_utils { 26 27/** 28 * Utility class used as a source of bytes. 29 */ 30class ANDROID_API Input { 31 public: 32 virtual ~Input(); 33 34 /** 35 * Open this Input. 36 * 37 * Returns OK on success, or a negative error code. 38 */ 39 virtual status_t open(); 40 41 /** 42 * Read bytes into the given buffer. At most, the number of bytes given in the 43 * count argument will be read. Bytes will be written into the given buffer starting 44 * at the index given in the offset argument. 45 * 46 * Returns the number of bytes read. If an error has occurred, the value pointed 47 * to by the given status_t pointer will be set to a negative error code. 48 */ 49 virtual size_t read(uint8_t* buf, size_t offset, size_t count, status_t* err) = 0; 50 51 /** 52 * Close the Input. It is not valid to call open on a previously closed Input. 53 * 54 * Returns OK on success, or a negative error code. 55 */ 56 virtual status_t close(); 57}; 58 59} /*namespace img_utils*/ 60} /*namespace android*/ 61 62 63#endif /*IMG_UTILS_INPUT_H*/ 64