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-rw-r--r--cbuffer.c71
1 files changed, 42 insertions, 29 deletions
diff --git a/cbuffer.c b/cbuffer.c
index a97c08e..89693ab 100644
--- a/cbuffer.c
+++ b/cbuffer.c
@@ -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 );