diff options
Diffstat (limited to 'cpukit/include/rtems/rtl/rtl-obj-comp.h')
| -rw-r--r-- | cpukit/include/rtems/rtl/rtl-obj-comp.h | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/cpukit/include/rtems/rtl/rtl-obj-comp.h b/cpukit/include/rtems/rtl/rtl-obj-comp.h new file mode 100644 index 0000000000..34bfa6ffa1 --- /dev/null +++ b/cpukit/include/rtems/rtl/rtl-obj-comp.h @@ -0,0 +1,122 @@ +/* + * COPYRIGHT (c) 2012 Chris Johns <chrisj@rtems.org> + * + * The license and distribution terms for this file may be + * found in the file LICENSE in this distribution or at + * http://www.rtems.org/license/LICENSE. + */ +/** + * @file + * + * @ingroup rtems_rtl + * + * @brief RTEMS Run-Time Linker Object File Compression manages a + * compressed stream of data. + * + * This is a simple interface to the object file cache to stream data from + * from a compressed object file. There is no ability to seek with the + * data from a compressed file. The module exists to allocate the output + * buffer when the loader starts and use the cache buffers will have been + * allocated. + */ + +#if !defined (_RTEMS_RTL_OBJ_COMP_H_) +#define _RTEMS_RTL_OBJ_COMP_H_ + +#include <rtems/rtl/rtl-obj-cache.h> + +#ifdef __cplusplus +extern "C" { +#endif /* __cplusplus */ + +/** + * The amount of input data read at a time from the file. + */ +#define RTEMS_RTL_DECOMP_INPUT_SIZE (256) + +/** + * The types of supported compression. + */ +#define RTEMS_RTL_COMP_NONE (0) +#define RTEMS_RTL_COMP_LZ77 (1) + +/** + * The compressed file. + */ +typedef struct rtems_rtl_obj_cpmp_s +{ + rtems_rtl_obj_cache_t* cache; /**< The cache provides the input + * buffer. */ + int fd; /**< The file descriptor. */ + int compression; /**< The type of compression. */ + off_t offset; /**< The base offset of the buffer. */ + size_t size; /**< The size of the output buffer. */ + size_t level; /**< The amount of data in the buffer. */ + uint8_t* buffer; /**< The buffer */ + uint32_t read; /**< The amount of data read. */ +} rtems_rtl_obj_comp_t; + +/** + * Return the input level. + */ +static inline uint32_t rtems_rtl_obj_comp_input (rtems_rtl_obj_comp_t* comp) +{ + return comp->read; +} + +/** + * Open a compressor allocating the output buffer. + * + * @param comp The compressor to initialise. + * @param size The size of the compressor's output buffer. + * @retval true The compressor is open. + * @retval false The compressor is not open. The RTL error is set. + */ +bool rtems_rtl_obj_comp_open (rtems_rtl_obj_comp_t* comp, + size_t size); + +/** + * Close a compressor. + * + * @param comp The compressor to close. + */ +void rtems_rtl_obj_comp_close (rtems_rtl_obj_comp_t* comp); + +/** + * Set the cache and offset in the file the compressed stream starts. + * + * @param comp The compressor to set the offset in. + * @param cache The cache to read the file in by. + * @param fd The file descriptor. Must be an open file. + * @param compression The type of compression being streamed. + * @param offset The offset in the file the compressed stream starts. + */ +void rtems_rtl_obj_comp_set (rtems_rtl_obj_comp_t* comp, + rtems_rtl_obj_cache_t* cache, + int fd, + int compression, + off_t offset); + +/** + * Read decompressed data. The length contains the amount of data that should + * be available in the cache and referenced by the buffer handle. It must be + * less than or equal to the size of the cache. This call will return the + * amount of data that is available. It can be less than you ask if the offset + * and size is past the end of the file. + * + * @param comp The compressor to read data from. + * @param buffer The buffer the output is written too. + * @param length The length of data to read. Can be modified to a + * lesser value and true is still returned so check it. + * @retval true The data referenced is in the cache. + * @retval false The read failed and the RTL error has been set. + */ +bool rtems_rtl_obj_comp_read (rtems_rtl_obj_comp_t* comp, + void* buffer, + size_t length); + +#ifdef __cplusplus +} +#endif /* __cplusplus */ + +#endif |