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Add some more control to the ring buffer.

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This commit is contained in:
Vreixo Formoso 2008-01-14 21:13:53 +01:00
parent 8bc1cf90a9
commit 9ebc4a1eef
9 changed files with 146 additions and 40 deletions
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8
demo/cat_buffer.c
View File

@ -42,7 +42,7 @@ void *write_function(void *arg)
int fd = open(data->path, O_RDONLY);
if (fd < 0) {
fprintf(stderr, "Writer thread error: Can't open file");
iso_ring_buffer_writer_close(data->rbuf);
iso_ring_buffer_writer_close(data->rbuf, 1);
pthread_exit(NULL);
}
@ -64,7 +64,7 @@ void *write_function(void *arg)
fprintf(stderr, "Writer finish: %d\n", res);
close(fd);
iso_ring_buffer_writer_close(data->rbuf);
iso_ring_buffer_writer_close(data->rbuf, 0);
pthread_exit(NULL);
}
@ -88,7 +88,7 @@ void *read_function(void *arg)
}
fprintf(stderr, "Reader finish: %d\n", res);
iso_ring_buffer_reader_close(data->rbuf);
iso_ring_buffer_reader_close(data->rbuf, 0);
pthread_exit(NULL);
}
@ -105,7 +105,7 @@ int main(int argc, char **argv)
return 1;
}
res = iso_ring_buffer_new(&data.rbuf);
res = iso_ring_buffer_new(1024, &data.rbuf);
if (res < 0) {
fprintf(stderr, "Can't create buffer\n");
return 1;

3
demo/iso.c
View File

@ -72,7 +72,8 @@ int main(int argc, char **argv)
NULL, /* output charset */
0, /* appendable */
0, /* ms_block */
NULL /* overwrite */
NULL, /* overwrite */
1024 /* fifo_size */
};
while ((c = getopt(argc, argv, optstring)) != -1) {

3
demo/iso_grow.c
View File

@ -55,7 +55,8 @@ int main(int argc, char **argv)
NULL, /* output charset */
0, /* appendable */
0, /* ms_block */
NULL /* overwrite */
NULL, /* overwrite */
1024 /* fifo_size */
};
struct iso_read_opts ropts = {
0, /* block */

3
demo/iso_modify.c
View File

@ -50,7 +50,8 @@ int main(int argc, char **argv)
NULL, /* output charset */
0, /* appendable */
0, /* ms_block */
NULL /* overwrite */
NULL, /* overwrite */
1024 /* fifo_size */
};
struct iso_read_opts ropts = {
0, /* block */

3
demo/iso_ms.c
View File

@ -50,7 +50,8 @@ int main(int argc, char **argv)
NULL, /* output charset */
0, /* appendable */
0, /* ms_block */
NULL /* overwrite */
NULL, /* overwrite */
1024 /* fifo_size */
};
struct iso_read_opts ropts = {
0, /* block */

107
src/buffer.c
View File

@ -18,19 +18,24 @@
#include "buffer.h"
#include "error.h"
#include "libburn/libburn.h"
#include "ecma119.h"
#include <pthread.h>
#include <string.h>
#define BUFFER_CAPACITY BLOCK_SIZE * BUFFER_SIZE
#ifndef MIN
# define MIN(a, b) (((a) < (b)) ? (a) : (b))
#endif
struct iso_ring_buffer
{
uint8_t buf[BLOCK_SIZE * BUFFER_SIZE];
uint8_t *buf;
/*
* Max number of bytes in buffer
*/
size_t cap;
/*
* Number of bytes available.
@ -41,9 +46,12 @@ struct iso_ring_buffer
size_t rpos;
size_t wpos;
/* flags to report if read or writer threads ends execution */
unsigned int rend :1;
unsigned int wend :1;
/*
* flags to report if read or writer threads ends execution
* 0 not finished, 1 finished ok, 2 finish with error
*/
unsigned int rend :2;
unsigned int wend :2;
/* just for statistical purposes */
unsigned int times_full;
@ -57,12 +65,16 @@ struct iso_ring_buffer
/**
* Create a new buffer.
*
* The created buffer can be freed with free(3)
* The created buffer should be freed with iso_ring_buffer_free()
*
* @param size
* Number of blocks in buffer. You should supply a number >= 32, otherwise
* size will be ignored and 32 will be used by default, which leads to a
* 64 KiB buffer.
* @return
* 1 success, < 0 error
*/
int iso_ring_buffer_new(IsoRingBuffer **rbuf)
int iso_ring_buffer_new(size_t size, IsoRingBuffer **rbuf)
{
IsoRingBuffer *buffer;
@ -75,6 +87,13 @@ int iso_ring_buffer_new(IsoRingBuffer **rbuf)
return ISO_MEM_ERROR;
}
buffer->cap = (size > 32 ? size : 32) * BLOCK_SIZE;
buffer->buf = malloc(buffer->cap);
if (buffer->buf == NULL) {
free(buffer);
return ISO_MEM_ERROR;
}
buffer->size = 0;
buffer->wpos = 0;
buffer->rpos = 0;
@ -95,6 +114,7 @@ int iso_ring_buffer_new(IsoRingBuffer **rbuf)
void iso_ring_buffer_free(IsoRingBuffer *buf)
{
free(buf->buf);
pthread_mutex_destroy(&buf->mutex);
pthread_cond_destroy(&buf->empty);
pthread_cond_destroy(&buf->full);
@ -128,11 +148,11 @@ int iso_ring_buffer_write(IsoRingBuffer *buf, uint8_t *data, size_t count)
pthread_mutex_lock(&buf->mutex);
while (buf->size == BUFFER_CAPACITY) {
while (buf->size == buf->cap) {
/*
* Note. There's only a writer, so we have no race conditions.
* Thus, the while(buf->size == BUFFER_CAPACITY) is used here
* Thus, the while(buf->size == buf->cap) is used here
* only to propertly detect the reader has been cancelled
*/
@ -146,12 +166,12 @@ int iso_ring_buffer_write(IsoRingBuffer *buf, uint8_t *data, size_t count)
pthread_cond_wait(&buf->full, &buf->mutex);
}
len = MIN(count - bytes_write, BUFFER_CAPACITY - buf->size);
if (buf->wpos + len > BUFFER_CAPACITY) {
len = BUFFER_CAPACITY - buf->wpos;
len = MIN(count - bytes_write, buf->cap - buf->size);
if (buf->wpos + len > buf->cap) {
len = buf->cap - buf->wpos;
}
memcpy(buf->buf + buf->wpos, data + bytes_write, len);
buf->wpos = (buf->wpos + len) % (BUFFER_CAPACITY);
buf->wpos = (buf->wpos + len) % (buf->cap);
bytes_write += len;
buf->size += len;
@ -202,11 +222,11 @@ int iso_ring_buffer_read(IsoRingBuffer *buf, uint8_t *dest, size_t count)
}
len = MIN(count - bytes_read, buf->size);
if (buf->rpos + len > BUFFER_CAPACITY) {
len = BUFFER_CAPACITY - buf->rpos;
if (buf->rpos + len > buf->cap) {
len = buf->cap - buf->rpos;
}
memcpy(dest + bytes_read, buf->buf + buf->rpos, len);
buf->rpos = (buf->rpos + len) % (BUFFER_CAPACITY);
buf->rpos = (buf->rpos + len) % (buf->cap);
bytes_read += len;
buf->size -= len;
@ -217,20 +237,20 @@ int iso_ring_buffer_read(IsoRingBuffer *buf, uint8_t *dest, size_t count)
return ISO_SUCCESS;
}
void iso_ring_buffer_writer_close(IsoRingBuffer *buf)
void iso_ring_buffer_writer_close(IsoRingBuffer *buf, int error)
{
pthread_mutex_lock(&buf->mutex);
buf->wend = 1;
buf->wend = error ? 2 : 1;
/* ensure no reader is waiting */
pthread_cond_signal(&buf->empty);
pthread_mutex_unlock(&buf->mutex);
}
void iso_ring_buffer_reader_close(IsoRingBuffer *buf)
void iso_ring_buffer_reader_close(IsoRingBuffer *buf, int error)
{
pthread_mutex_lock(&buf->mutex);
buf->rend = 1;
buf->rend = error ? 2 : 1;
/* ensure no writer is waiting */
pthread_cond_signal(&buf->full);
@ -252,3 +272,48 @@ unsigned int iso_ring_buffer_get_times_empty(IsoRingBuffer *buf)
{
return buf->times_empty;
}
/**
* Get the status of the buffer used by a burn_source.
*
* @param b
* A burn_source previously obtained with
* iso_image_create_burn_source().
* @param size
* Will be filled with the total size of the buffer, in bytes
* @param free_bytes
* Will be filled with the bytes currently available in buffer
* @return
* < 0 error, > 0 state:
* 1="active" : input and consumption are active
* 2="ending" : input has ended without error
* 3="failing" : input had error and ended,
* 5="abandoned" : consumption has ended prematurely
* 6="ended" : consumption has ended without input error
* 7="aborted" : consumption has ended after input error
*/
int iso_ring_buffer_get_status(struct burn_source *b, size_t *size,
size_t *free_bytes)
{
int ret;
IsoRingBuffer *buf;
if (b == NULL) {
return ISO_NULL_POINTER;
}
buf = ((Ecma119Image*)(b->data))->buffer;
/* get mutex */
pthread_mutex_lock(&buf->mutex);
if (size) {
*size = buf->cap;
}
if (free_bytes) {
*free_bytes = buf->size;
}
ret = (buf->rend + 1) + (buf->wend ? 4 : 0);
pthread_mutex_unlock(&buf->mutex);
return ret;
}

20
src/buffer.h
View File

@ -12,21 +12,23 @@
#include <stdlib.h>
#include <stdint.h>
/* 2 MB buffer */
#define BLOCK_SIZE 2048
#define BUFFER_SIZE 1024
typedef struct iso_ring_buffer IsoRingBuffer;
/**
* Create a new buffer.
*
* The created buffer can be freed with iso_ring_buffer_free(3)
* The created buffer should be freed with iso_ring_buffer_free()
*
* @param size
* Number of blocks in buffer. You should supply a number >= 32, otherwise
* size will be ignored and 32 will be used by default, which leads to a
* 64 KiB buffer.
* @return
* 1 success, < 0 error
*/
int iso_ring_buffer_new(IsoRingBuffer **rbuf);
int iso_ring_buffer_new(size_t size, IsoRingBuffer **rbuf);
/**
* Free a given buffer
@ -64,15 +66,21 @@ int iso_ring_buffer_read(IsoRingBuffer *buf, uint8_t *dest, size_t count);
* Close the buffer (to be called by the writer).
* You have to explicity close the buffer when you don't have more data to
* write, otherwise reader will be waiting forever.
*
* @param error
* Writer has finished prematurely due to an error
*/
void iso_ring_buffer_writer_close(IsoRingBuffer *buf);
void iso_ring_buffer_writer_close(IsoRingBuffer *buf, int error);
/**
* Close the buffer (to be called by the reader).
* If for any reason you don't want to read more data, you need to call this
* to let the writer thread finish.
*
* @param error
* Reader has finished prematurely due to an error
*/
void iso_ring_buffer_reader_close(IsoRingBuffer *buf);
void iso_ring_buffer_reader_close(IsoRingBuffer *buf, int error);
/**
* Get the times the buffer was full.

8
src/ecma119.c
View File

@ -808,13 +808,13 @@ void *write_function(void *arg)
}
}
iso_ring_buffer_writer_close(target->buffer);
iso_ring_buffer_writer_close(target->buffer, 0);
pthread_exit(NULL);
write_error: ;
iso_msg_fatal(target->image->messenger, LIBISO_WRITE_ERROR,
"Image write error, code %d", res);
iso_ring_buffer_writer_close(target->buffer);
iso_ring_buffer_writer_close(target->buffer, 1);
pthread_exit(NULL);
}
@ -976,7 +976,7 @@ int ecma119_image_new(IsoImage *src, Ecma119WriteOpts *opts, Ecma119Image **img)
}
/* create the ring buffer */
ret = iso_ring_buffer_new(&target->buffer);
ret = iso_ring_buffer_new(opts->fifo_size, &target->buffer);
if (ret < 0) {
goto target_cleanup;
}
@ -1097,7 +1097,7 @@ static void bs_free_data(struct burn_source *bs)
Ecma119Image *target = (Ecma119Image*)bs->data;
/* forces writer to stop if it is still running */
iso_ring_buffer_reader_close(target->buffer);
iso_ring_buffer_reader_close(target->buffer, 0);
/* wait until writer thread finishes */
pthread_join(target->wthread, NULL);

29
src/libisofs.h
View File

@ -196,6 +196,13 @@ typedef struct
* enought.
*/
uint8_t *overwrite;
/**
* Size, in number of blocks, of the FIFO buffer used between the writer
* thread and the burn_source. You have to provide at least a 32 blocks
* buffer.
*/
size_t fifo_size;
} Ecma119WriteOpts;
typedef struct Iso_Data_Source IsoDataSource;
@ -1221,6 +1228,28 @@ void iso_data_source_unref(IsoDataSource *src);
*/
int iso_data_source_new_from_file(const char *path, IsoDataSource **src);
/**
* Get the status of the buffer used by a burn_source.
*
* @param b
* A burn_source previously obtained with
* iso_image_create_burn_source().
* @param size
* Will be filled with the total size of the buffer, in bytes
* @param free_bytes
* Will be filled with the bytes currently available in buffer
* @return
* < 0 error, > 0 state:
* 1="active" : input and consumption are active
* 2="ending" : input has ended without error
* 3="failing" : input had error and ended,
* 5="abandoned" : consumption has ended prematurely
* 6="ended" : consumption has ended without input error
* 7="aborted" : consumption has ended after input error
*/
int iso_ring_buffer_get_status(struct burn_source *b, size_t *size,
size_t *free_bytes);
#define ISO_MSGS_MESSAGE_LEN 4096
/**