diff options
Diffstat (limited to 'cbuffer.c')
| -rw-r--r-- | cbuffer.c | 71 |
1 files changed, 42 insertions, 29 deletions
@@ -1,5 +1,5 @@ /* Lzlib - Compression library for the lzip format - Copyright (C) 2009-2015 Antonio Diaz Diaz. + Copyright (C) 2009-2016 Antonio Diaz Diaz. This library is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -28,56 +28,68 @@ struct Circular_buffer { uint8_t * buffer; - int buffer_size; /* capacity == buffer_size - 1 */ - int get; /* buffer is empty when get == put */ - int put; + unsigned buffer_size; /* capacity == buffer_size - 1 */ + unsigned get; /* buffer is empty when get == put */ + unsigned put; }; static inline void Cb_reset( struct Circular_buffer * const cb ) { cb->get = 0; cb->put = 0; } static inline bool Cb_init( struct Circular_buffer * const cb, - const int buf_size ) + const unsigned buf_size ) { - cb->buffer = (uint8_t *)malloc( buf_size + 1 ); cb->buffer_size = buf_size + 1; cb->get = 0; cb->put = 0; + cb->buffer = + ( cb->buffer_size > 1 ) ? (uint8_t *)malloc( cb->buffer_size ) : 0; return ( cb->buffer != 0 ); } static inline void Cb_free( struct Circular_buffer * const cb ) { free( cb->buffer ); cb->buffer = 0; } -static inline int Cb_used_bytes( const struct Circular_buffer * const cb ) - { return ( (cb->get <= cb->put) ? 0 : cb->buffer_size ) + cb->put - cb->get; } +static inline unsigned Cb_used_bytes( const struct Circular_buffer * const cb ) + { return ( (cb->get <= cb->put) ? 0 : cb->buffer_size ) + cb->put - cb->get; } -static inline int Cb_free_bytes( const struct Circular_buffer * const cb ) - { return ( (cb->get <= cb->put) ? cb->buffer_size : 0 ) - cb->put + cb->get - 1; } +static inline unsigned Cb_free_bytes( const struct Circular_buffer * const cb ) + { return ( (cb->get <= cb->put) ? cb->buffer_size : 0 ) - cb->put + cb->get - 1; } static inline uint8_t Cb_get_byte( struct Circular_buffer * const cb ) - { - const uint8_t b = cb->buffer[cb->get]; - if( ++cb->get >= cb->buffer_size ) cb->get = 0; - return b; - } + { + const uint8_t b = cb->buffer[cb->get]; + if( ++cb->get >= cb->buffer_size ) cb->get = 0; + return b; + } static inline void Cb_put_byte( struct Circular_buffer * const cb, const uint8_t b ) - { - cb->buffer[cb->put] = b; - if( ++cb->put >= cb->buffer_size ) cb->put = 0; - } + { + cb->buffer[cb->put] = b; + if( ++cb->put >= cb->buffer_size ) cb->put = 0; + } + + +static bool Cb_unread_data( struct Circular_buffer * const cb, + const unsigned size ) + { + if( size > Cb_free_bytes( cb ) ) return false; + if( cb->get >= size ) cb->get -= size; + else cb->get = cb->buffer_size - size + cb->get; + return true; + } /* Copies up to 'out_size' bytes to 'out_buffer' and updates 'get'. Returns the number of bytes copied. */ -static int Cb_read_data( struct Circular_buffer * const cb, - uint8_t * const out_buffer, const int out_size ) +static unsigned Cb_read_data( struct Circular_buffer * const cb, + uint8_t * const out_buffer, + const unsigned out_size ) { - int size = 0; - if( out_size <= 0 ) return 0; + unsigned size = 0; + if( out_size == 0 ) return 0; if( cb->get > cb->put ) { size = min( cb->buffer_size - cb->get, out_size ); @@ -90,7 +102,7 @@ static int Cb_read_data( struct Circular_buffer * const cb, } if( cb->get < cb->put ) { - const int size2 = min( cb->put - cb->get, out_size - size ); + const unsigned size2 = min( cb->put - cb->get, out_size - size ); if( size2 > 0 ) { memcpy( out_buffer + size, cb->buffer + cb->get, size2 ); @@ -105,11 +117,12 @@ static int Cb_read_data( struct Circular_buffer * const cb, /* Copies up to 'in_size' bytes from 'in_buffer' and updates 'put'. Returns the number of bytes copied. */ -static int Cb_write_data( struct Circular_buffer * const cb, - const uint8_t * const in_buffer, const int in_size ) +static unsigned Cb_write_data( struct Circular_buffer * const cb, + const uint8_t * const in_buffer, + const unsigned in_size ) { - int size = 0; - if( in_size < 0 ) return 0; + unsigned size = 0; + if( in_size == 0 ) return 0; if( cb->put >= cb->get ) { size = min( cb->buffer_size - cb->put - (cb->get == 0), in_size ); @@ -122,7 +135,7 @@ static int Cb_write_data( struct Circular_buffer * const cb, } if( cb->put < cb->get ) { - const int size2 = min( cb->get - cb->put - 1, in_size - size ); + const unsigned size2 = min( cb->get - cb->put - 1, in_size - size ); if( size2 > 0 ) { memcpy( cb->buffer + cb->put, in_buffer + size, size2 ); |