From 359d71e90050a8b83f7bc7d2ecd4ff29c477cc22 Mon Sep 17 00:00:00 2001 From: David Oberhollenzer Date: Sun, 26 Jun 2022 22:51:27 +0200 Subject: Cleanup: rename libfstream to libio, split headers Signed-off-by: David Oberhollenzer --- include/io/istream.h | 128 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 128 insertions(+) create mode 100644 include/io/istream.h (limited to 'include/io/istream.h') diff --git a/include/io/istream.h b/include/io/istream.h new file mode 100644 index 0000000..567d7e3 --- /dev/null +++ b/include/io/istream.h @@ -0,0 +1,128 @@ +/* SPDX-License-Identifier: GPL-3.0-or-later */ +/* + * istream.h + * + * Copyright (C) 2019 David Oberhollenzer + */ +#ifndef IO_ISTREAM_H +#define IO_ISTREAM_H + +#include "sqfs/predef.h" + +/** + * @struct istream_t + * + * @extends sqfs_object_t + * + * @brief A sequential, read-only data stream. + */ +typedef struct istream_t { + sqfs_object_t base; + + size_t buffer_used; + size_t buffer_offset; + bool eof; + + sqfs_u8 *buffer; + + int (*precache)(struct istream_t *strm); + + const char *(*get_filename)(struct istream_t *strm); +} istream_t; + +enum { + ISTREAM_LINE_LTRIM = 0x01, + ISTREAM_LINE_RTRIM = 0x02, + ISTREAM_LINE_SKIP_EMPTY = 0x04, +}; + +#ifdef __cplusplus +extern "C" { +#endif + +/** + * @brief Read a line of text from an input stream + * + * @memberof istream_t + * + * The line returned is allocated using malloc and must subsequently be + * freed when it is no longer needed. The line itself is always null-terminated + * and never includes the line break characters (LF or CR-LF). + * + * If the flag @ref ISTREAM_LINE_LTRIM is set, leading white space characters + * are removed. If the flag @ref ISTREAM_LINE_RTRIM is set, trailing white space + * characters are remvoed. + * + * If the flag @ref ISTREAM_LINE_SKIP_EMPTY is set and a line is discovered to + * be empty (after the optional trimming), the function discards the empty line + * and retries. The given line_num pointer is used to increment the line + * number. + * + * @param strm A pointer to an input stream. + * @param out Returns a pointer to a line on success. + * @param line_num This is incremented if lines are skipped. + * @param flags A combination of flags controling the functions behaviour. + * + * @return Zero on success, a negative value on error, a positive value if + * end-of-file was reached without reading any data. + */ +SQFS_INTERNAL int istream_get_line(istream_t *strm, char **out, + size_t *line_num, int flags); + +/** + * @brief Read data from an input stream + * + * @memberof istream_t + * + * @param strm A pointer to an input stream. + * @param data A buffer to read into. + * @param size The number of bytes to read into the buffer. + * + * @return The number of bytes actually read on success, -1 on failure, + * 0 on end-of-file. + */ +SQFS_INTERNAL sqfs_s32 istream_read(istream_t *strm, void *data, size_t size); + +/** + * @brief Adjust and refill the internal buffer of an input stream + * + * @memberof istream_t + * + * This function resets the buffer offset of an input stream (moving any unread + * data up front if it has to) and calls an internal callback of the input + * stream to fill the rest of the buffer to the extent possible. + * + * @param strm A pointer to an input stream. + * + * @return 0 on success, -1 on failure. + */ +SQFS_INTERNAL int istream_precache(istream_t *strm); + +/** + * @brief Get the underlying filename of an input stream. + * + * @memberof istream_t + * + * @param strm The input stream to get the filename from. + * + * @return A string holding the underlying filename. + */ +SQFS_INTERNAL const char *istream_get_filename(istream_t *strm); + +/** + * @brief Skip over a number of bytes in an input stream. + * + * @memberof istream_t + * + * @param strm A pointer to an input stream. + * @param size The number of bytes to seek forward. + * + * @return Zero on success, -1 on failure. + */ +SQFS_INTERNAL int istream_skip(istream_t *strm, sqfs_u64 size); + +#ifdef __cplusplus +} +#endif + +#endif /* IO_ISTREAM_H */ -- cgit v1.2.3