2 * This file is part of DisOrder
3 * Copyright (C) 2010 Richard Kettlewell
5 * This program is free software: you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation, either version 3 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program. If not, see <http://www.gnu.org/licenses/>.
18 /** @file lib/hreader.h
19 * @brief Hands-off reader - read files without keeping them open
26 /** @brief A hands-off reader
28 * Allows files to be read without holding them open.
31 const char *path; /* file to read */
32 off_t offset; /* how far we've read so far */
33 char *buffer; /* input buffer */
34 size_t bufsize; /* buffer size */
35 size_t bytes; /* size of last read */
36 size_t consumed; /* bytes consumed by caller from last read */
39 /** @brief Initialize a hands-off reader
40 * @param path File to read
41 * @param h Reader to initialize
43 void hreader_init(const char *path, struct hreader *h);
45 /** @brief Read some bytes
46 * @param h Reader to read from
47 * @param buffer Where to store bytes
48 * @param n Maximum bytes to read
49 * @return Bytes read, or 0 at EOF, or -1 on error
51 int hreader_read(struct hreader *h, void *buffer, size_t n);
53 /** @brief Read more bytes
54 * @param h Reader to update
55 * @return Bytes available to read
57 * If not all bytes were consumed so far then just returns the number
58 * of bytes left to consume.
60 int hreader_fill(struct hreader *h);
62 /** @brief Consume some bytes
63 * @param h Reader to update
64 * @param n Bytes to consume
66 void hreader_consume(struct hreader *h, size_t n);
68 #endif /* HREADER_H */