diff options
| -rw-r--r-- | plugins/alsa/CMakeLists.txt | 2 | ||||
| -rw-r--r-- | plugins/alsa/alsa-ringbuf.c | 50 | ||||
| -rw-r--r-- | plugins/alsa/alsa-ringbuf.h | 27 | ||||
| -rw-r--r-- | plugins/alsa/ringbuf.c | 347 | ||||
| -rw-r--r-- | plugins/alsa/ringbuf.h | 243 | ||||
| -rw-r--r-- | plugins/alsa/time_utils.c | 17 | ||||
| -rw-r--r-- | plugins/alsa/time_utils.h | 9 |
7 files changed, 694 insertions, 1 deletions
diff --git a/plugins/alsa/CMakeLists.txt b/plugins/alsa/CMakeLists.txt index 687ccb2..2e93177 100644 --- a/plugins/alsa/CMakeLists.txt +++ b/plugins/alsa/CMakeLists.txt @@ -19,7 +19,7 @@ PROJECT_TARGET_ADD(alsa-softmixer) - file(GLOB SOURCE_FILES "alsa-*.c") + file(GLOB SOURCE_FILES "alsa-*.c" ringbuf.c time_utils.c) # Define targets ADD_LIBRARY(${TARGET_NAME} MODULE ${SOURCE_FILES}) diff --git a/plugins/alsa/alsa-ringbuf.c b/plugins/alsa/alsa-ringbuf.c new file mode 100644 index 0000000..2d77e4c --- /dev/null +++ b/plugins/alsa/alsa-ringbuf.c @@ -0,0 +1,50 @@ +#include "alsa-ringbuf.h" + +alsa_ringbuf_t * alsa_ringbuf_new(snd_pcm_uframes_t capacity, size_t frameSize) { + alsa_ringbuf_t * rb = malloc(sizeof(alsa_ringbuf_t)); + + rb->rbuf = ringbuf_new(capacity*frameSize); + rb->frameSize = frameSize; + return rb; +} + +snd_pcm_uframes_t alsa_ringbuf_buffer_size(const alsa_ringbuf_t *rb) { + return ringbuf_buffer_size(rb->rbuf)/rb->frameSize; +} + +void alsa_ringbuf_free(alsa_ringbuf_t *rb) { + ringbuf_free(&rb->rbuf); + free(rb); +} + +void alsa_ringbuf_reset(alsa_ringbuf_t * rb) { + ringbuf_reset(rb->rbuf); +} + +snd_pcm_uframes_t alsa_ringbuf_capacity(const alsa_ringbuf_t *rb) { + return ringbuf_capacity(rb->rbuf)/rb->frameSize; +} + +snd_pcm_uframes_t alsa_ringbuf_frames_free(const alsa_ringbuf_t *rb) { + return ringbuf_bytes_free(rb->rbuf)/rb->frameSize; +} + +snd_pcm_uframes_t alsa_ringbuf_frames_used(const alsa_ringbuf_t *rb) { + return ringbuf_bytes_used(rb->rbuf)/rb->frameSize; +} + +bool alsa_ringbuf_is_full(const alsa_ringbuf_t *rb) { + return ringbuf_is_full(rb->rbuf)==1; +} + +bool alsa_ringbuf_is_empty(const alsa_ringbuf_t *rb) { + return ringbuf_is_empty(rb->rbuf)==1; +} + +void alsa_ringbuf_frames_push(alsa_ringbuf_t * rb, const void * src, snd_pcm_uframes_t nb) { + ringbuf_memcpy_into(rb->rbuf, src, nb*rb->frameSize); +} + +void alsa_ringbuf_frames_pop(alsa_ringbuf_t * rb, void * dst, snd_pcm_uframes_t nb) { + ringbuf_memcpy_from(dst, rb->rbuf, nb*rb->frameSize); +} diff --git a/plugins/alsa/alsa-ringbuf.h b/plugins/alsa/alsa-ringbuf.h new file mode 100644 index 0000000..5ecc7fe --- /dev/null +++ b/plugins/alsa/alsa-ringbuf.h @@ -0,0 +1,27 @@ +#ifndef __INC_ALSA_RINGBUF_H +#define __INC_ALSA_RINGBUF_H + +#include "ringbuf.h" + +#include <alsa/asoundlib.h> +#include <stdbool.h> + +typedef struct { + ringbuf_t rbuf; + size_t frameSize; +} alsa_ringbuf_t ; + +extern alsa_ringbuf_t * alsa_ringbuf_new(snd_pcm_uframes_t capacity, size_t frameSize); +extern snd_pcm_uframes_t alsa_ringbuf_buffer_size(const alsa_ringbuf_t *rb); +extern void alsa_ringbuf_free(alsa_ringbuf_t *rb); +extern void alsa_ringbuf_reset(alsa_ringbuf_t *rb); +extern snd_pcm_uframes_t alsa_ringbuf_capacity(const alsa_ringbuf_t *rb); +extern snd_pcm_uframes_t alsa_ringbuf_frames_free(const alsa_ringbuf_t *rb); +extern snd_pcm_uframes_t alsa_ringbuf_frames_used(const alsa_ringbuf_t *rb); +extern bool alsa_ringbuf_is_full(const alsa_ringbuf_t *rb); +extern bool alsa_ringbuf_is_empty(const alsa_ringbuf_t *rb); + +extern void alsa_ringbuf_frames_push(alsa_ringbuf_t * rb, const void * buf, snd_pcm_uframes_t nb); +extern void alsa_ringbuf_frames_pop(alsa_ringbuf_t * rb, void * buf, snd_pcm_uframes_t nb); + +#endif /* __INC_ALSA_RINGBUF_H */ diff --git a/plugins/alsa/ringbuf.c b/plugins/alsa/ringbuf.c new file mode 100644 index 0000000..b18ddb6 --- /dev/null +++ b/plugins/alsa/ringbuf.c @@ -0,0 +1,347 @@ +/* + * ringbuf.c - C ring buffer (FIFO) implementation. + * + * Written in 2011 by Drew Hess <dhess-src@bothan.net>. + * + * To the extent possible under law, the author(s) have dedicated all + * copyright and related and neighboring rights to this software to + * the public domain worldwide. This software is distributed without + * any warranty. + * + * You should have received a copy of the CC0 Public Domain Dedication + * along with this software. If not, see + * <http://creativecommons.org/publicdomain/zero/1.0/>. + */ + +#include "ringbuf.h" + +#include <stdint.h> +#include <stdlib.h> +#include <string.h> +#include <sys/types.h> +#include <unistd.h> +#include <sys/param.h> +#include <assert.h> + +/* + * The code is written for clarity, not cleverness or performance, and + * contains many assert()s to enforce invariant assumptions and catch + * bugs. Feel free to optimize the code and to remove asserts for use + * in your own projects, once you're comfortable that it functions as + * intended. + */ + +struct ringbuf_t +{ + uint8_t *buf; + uint8_t *head, *tail; + size_t size; +}; + +ringbuf_t +ringbuf_new(size_t capacity) +{ + ringbuf_t rb = malloc(sizeof(struct ringbuf_t)); + if (rb) { + + /* One byte is used for detecting the full condition. */ + rb->size = capacity + 1; + rb->buf = malloc(rb->size); + if (rb->buf) + ringbuf_reset(rb); + else { + free(rb); + return 0; + } + } + return rb; +} + +size_t +ringbuf_buffer_size(const struct ringbuf_t *rb) +{ + return rb->size; +} + +void +ringbuf_reset(ringbuf_t rb) +{ + rb->head = rb->tail = rb->buf; +} + +void +ringbuf_free(ringbuf_t *rb) +{ + assert(rb && *rb); + free((*rb)->buf); + free(*rb); + *rb = 0; +} + +size_t +ringbuf_capacity(const struct ringbuf_t *rb) +{ + return ringbuf_buffer_size(rb) - 1; +} + +/* + * Return a pointer to one-past-the-end of the ring buffer's + * contiguous buffer. You shouldn't normally need to use this function + * unless you're writing a new ringbuf_* function. + */ +static const uint8_t * +ringbuf_end(const struct ringbuf_t *rb) +{ + return rb->buf + ringbuf_buffer_size(rb); +} + +size_t +ringbuf_bytes_free(const struct ringbuf_t *rb) +{ + if (rb->head >= rb->tail) + return ringbuf_capacity(rb) - (rb->head - rb->tail); + else + return rb->tail - rb->head - 1; +} + +size_t +ringbuf_bytes_used(const struct ringbuf_t *rb) +{ + return ringbuf_capacity(rb) - ringbuf_bytes_free(rb); +} + +int +ringbuf_is_full(const struct ringbuf_t *rb) +{ + return ringbuf_bytes_free(rb) == 0; +} + +int +ringbuf_is_empty(const struct ringbuf_t *rb) +{ + return ringbuf_bytes_free(rb) == ringbuf_capacity(rb); +} + +const void * +ringbuf_tail(const struct ringbuf_t *rb) +{ + return rb->tail; +} + +const void * +ringbuf_head(const struct ringbuf_t *rb) +{ + return rb->head; +} + +/* + * Given a ring buffer rb and a pointer to a location within its + * contiguous buffer, return the a pointer to the next logical + * location in the ring buffer. + */ +static uint8_t * +ringbuf_nextp(ringbuf_t rb, const uint8_t *p) +{ + /* + * The assert guarantees the expression (++p - rb->buf) is + * non-negative; therefore, the modulus operation is safe and + * portable. + */ + assert((p >= rb->buf) && (p < ringbuf_end(rb))); + return rb->buf + ((++p - rb->buf) % ringbuf_buffer_size(rb)); +} + +size_t +ringbuf_findchr(const struct ringbuf_t *rb, int c, size_t offset) +{ + const uint8_t *bufend = ringbuf_end(rb); + size_t bytes_used = ringbuf_bytes_used(rb); + if (offset >= bytes_used) + return bytes_used; + + const uint8_t *start = rb->buf + + (((rb->tail - rb->buf) + offset) % ringbuf_buffer_size(rb)); + assert(bufend > start); + size_t n = MIN(bufend - start, bytes_used - offset); + const uint8_t *found = memchr(start, c, n); + if (found) + return offset + (found - start); + else + return ringbuf_findchr(rb, c, offset + n); +} + +size_t +ringbuf_memset(ringbuf_t dst, int c, size_t len) +{ + const uint8_t *bufend = ringbuf_end(dst); + size_t nwritten = 0; + size_t count = MIN(len, ringbuf_buffer_size(dst)); + int overflow = count > ringbuf_bytes_free(dst); + + while (nwritten != count) { + + /* don't copy beyond the end of the buffer */ + assert(bufend > dst->head); + size_t n = MIN(bufend - dst->head, count - nwritten); + memset(dst->head, c, n); + dst->head += n; + nwritten += n; + + /* wrap? */ + if (dst->head == bufend) + dst->head = dst->buf; + } + + if (overflow) { + dst->tail = ringbuf_nextp(dst, dst->head); + assert(ringbuf_is_full(dst)); + } + + return nwritten; +} + +void * +ringbuf_memcpy_into(ringbuf_t dst, const void *src, size_t count) +{ + const uint8_t *u8src = src; + const uint8_t *bufend = ringbuf_end(dst); + int overflow = count > ringbuf_bytes_free(dst); + size_t nread = 0; + + while (nread != count) { + /* don't copy beyond the end of the buffer */ + assert(bufend > dst->head); + size_t n = MIN(bufend - dst->head, count - nread); + memcpy(dst->head, u8src + nread, n); + dst->head += n; + nread += n; + + /* wrap? */ + if (dst->head == bufend) + dst->head = dst->buf; + } + + if (overflow) { + dst->tail = ringbuf_nextp(dst, dst->head); + assert(ringbuf_is_full(dst)); + } + + return dst->head; +} + +ssize_t +ringbuf_read(int fd, ringbuf_t rb, size_t count) +{ + const uint8_t *bufend = ringbuf_end(rb); + size_t nfree = ringbuf_bytes_free(rb); + + /* don't write beyond the end of the buffer */ + assert(bufend > rb->head); + count = MIN(bufend - rb->head, count); + ssize_t n = read(fd, rb->head, count); + if (n > 0) { + assert(rb->head + n <= bufend); + rb->head += n; + + /* wrap? */ + if (rb->head == bufend) + rb->head = rb->buf; + + /* fix up the tail pointer if an overflow occurred */ + if (n > nfree) { + rb->tail = ringbuf_nextp(rb, rb->head); + assert(ringbuf_is_full(rb)); + } + } + + return n; +} + +void * +ringbuf_memcpy_from(void *dst, ringbuf_t src, size_t count) +{ + size_t bytes_used = ringbuf_bytes_used(src); + if (count > bytes_used) + return 0; + + uint8_t *u8dst = dst; + const uint8_t *bufend = ringbuf_end(src); + size_t nwritten = 0; + while (nwritten != count) { + assert(bufend > src->tail); + size_t n = MIN(bufend - src->tail, count - nwritten); + memcpy(u8dst + nwritten, src->tail, n); + src->tail += n; + nwritten += n; + + /* wrap ? */ + if (src->tail == bufend) + src->tail = src->buf; + } + + assert(count + ringbuf_bytes_used(src) == bytes_used); + return src->tail; +} + +ssize_t +ringbuf_write(int fd, ringbuf_t rb, size_t count) +{ + size_t bytes_used = ringbuf_bytes_used(rb); + if (count > bytes_used) + return 0; + + const uint8_t *bufend = ringbuf_end(rb); + assert(bufend > rb->head); + count = MIN(bufend - rb->tail, count); + ssize_t n = write(fd, rb->tail, count); + if (n > 0) { + assert(rb->tail + n <= bufend); + rb->tail += n; + + /* wrap? */ + if (rb->tail == bufend) + rb->tail = rb->buf; + + assert(n + ringbuf_bytes_used(rb) == bytes_used); + } + + return n; +} + +void * +ringbuf_copy(ringbuf_t dst, ringbuf_t src, size_t count) +{ + size_t src_bytes_used = ringbuf_bytes_used(src); + if (count > src_bytes_used) + return 0; + int overflow = count > ringbuf_bytes_free(dst); + + const uint8_t *src_bufend = ringbuf_end(src); + const uint8_t *dst_bufend = ringbuf_end(dst); + size_t ncopied = 0; + while (ncopied != count) { + assert(src_bufend > src->tail); + size_t nsrc = MIN(src_bufend - src->tail, count - ncopied); + assert(dst_bufend > dst->head); + size_t n = MIN(dst_bufend - dst->head, nsrc); + memcpy(dst->head, src->tail, n); + src->tail += n; + dst->head += n; + ncopied += n; + + /* wrap ? */ + if (src->tail == src_bufend) + src->tail = src->buf; + if (dst->head == dst_bufend) + dst->head = dst->buf; + } + + assert(count + ringbuf_bytes_used(src) == src_bytes_used); + + if (overflow) { + dst->tail = ringbuf_nextp(dst, dst->head); + assert(ringbuf_is_full(dst)); + } + + return dst->head; +} diff --git a/plugins/alsa/ringbuf.h b/plugins/alsa/ringbuf.h new file mode 100644 index 0000000..c72bfae --- /dev/null +++ b/plugins/alsa/ringbuf.h @@ -0,0 +1,243 @@ +#ifndef INCLUDED_RINGBUF_H +#define INCLUDED_RINGBUF_H + +/* + * ringbuf.h - C ring buffer (FIFO) interface. + * + * Written in 2011 by Drew Hess <dhess-src@bothan.net>. + * + * To the extent possible under law, the author(s) have dedicated all + * copyright and related and neighboring rights to this software to + * the public domain worldwide. This software is distributed without + * any warranty. + * + * You should have received a copy of the CC0 Public Domain Dedication + * along with this software. If not, see + * <http://creativecommons.org/publicdomain/zero/1.0/>. + */ + +/* + * A byte-addressable ring buffer FIFO implementation. + * + * The ring buffer's head pointer points to the starting location + * where data should be written when copying data *into* the buffer + * (e.g., with ringbuf_read). The ring buffer's tail pointer points to + * the starting location where data should be read when copying data + * *from* the buffer (e.g., with ringbuf_write). + */ + +#include <stddef.h> +#include <sys/types.h> + +typedef struct ringbuf_t *ringbuf_t; + +/* + * Create a new ring buffer with the given capacity (usable + * bytes). Note that the actual internal buffer size may be one or + * more bytes larger than the usable capacity, for bookkeeping. + * + * Returns the new ring buffer object, or 0 if there's not enough + * memory to fulfill the request for the given capacity. + */ +ringbuf_t +ringbuf_new(size_t capacity); + +/* + * The size of the internal buffer, in bytes. One or more bytes may be + * unusable in order to distinguish the "buffer full" state from the + * "buffer empty" state. + * + * For the usable capacity of the ring buffer, use the + * ringbuf_capacity function. + */ +size_t +ringbuf_buffer_size(const struct ringbuf_t *rb); + +/* + * Deallocate a ring buffer, and, as a side effect, set the pointer to + * 0. + */ +void +ringbuf_free(ringbuf_t *rb); + +/* + * Reset a ring buffer to its initial state (empty). + */ +void +ringbuf_reset(ringbuf_t rb); + +/* + * The usable capacity of the ring buffer, in bytes. Note that this + * value may be less than the ring buffer's internal buffer size, as + * returned by ringbuf_buffer_size. + */ +size_t +ringbuf_capacity(const struct ringbuf_t *rb); + +/* + * The number of free/available bytes in the ring buffer. This value + * is never larger than the ring buffer's usable capacity. + */ +size_t +ringbuf_bytes_free(const struct ringbuf_t *rb); + +/* + * The number of bytes currently being used in the ring buffer. This + * value is never larger than the ring buffer's usable capacity. + */ +size_t +ringbuf_bytes_used(const struct ringbuf_t *rb); + +int +ringbuf_is_full(const struct ringbuf_t *rb); + +int +ringbuf_is_empty(const struct ringbuf_t *rb); + +/* + * Const access to the head and tail pointers of the ring buffer. + */ +const void * +ringbuf_tail(const struct ringbuf_t *rb); + +const void * +ringbuf_head(const struct ringbuf_t *rb); + +/* + * Locate the first occurrence of character c (converted to an + * unsigned char) in ring buffer rb, beginning the search at offset + * bytes from the ring buffer's tail pointer. The function returns the + * offset of the character from the ring buffer's tail pointer, if + * found. If c does not occur in the ring buffer, the function returns + * the number of bytes used in the ring buffer. + * + * Note that the offset parameter and the returned offset are logical + * offsets from the tail pointer, not necessarily linear offsets. + */ +size_t +ringbuf_findchr(const struct ringbuf_t *rb, int c, size_t offset); + +/* + * Beginning at ring buffer dst's head pointer, fill the ring buffer + * with a repeating sequence of len bytes, each of value c (converted + * to an unsigned char). len can be as large as you like, but the + * function will never write more than ringbuf_buffer_size(dst) bytes + * in a single invocation, since that size will cause all bytes in the + * ring buffer to be written exactly once each. + * + * Note that if len is greater than the number of free bytes in dst, + * the ring buffer will overflow. When an overflow occurs, the state + * of the ring buffer is guaranteed to be consistent, including the + * head and tail pointers; old data will simply be overwritten in FIFO + * fashion, as needed. However, note that, if calling the function + * results in an overflow, the value of the ring buffer's tail pointer + * may be different than it was before the function was called. + * + * Returns the actual number of bytes written to dst: len, if + * len < ringbuf_buffer_size(dst), else ringbuf_buffer_size(dst). + */ +size_t +ringbuf_memset(ringbuf_t dst, int c, size_t len); + +/* + * Copy n bytes from a contiguous memory area src into the ring buffer + * dst. Returns the ring buffer's new head pointer. + * + * It is possible to copy more data from src than is available in the + * buffer; i.e., it's possible to overflow the ring buffer using this + * function. When an overflow occurs, the state of the ring buffer is + * guaranteed to be consistent, including the head and tail pointers; + * old data will simply be overwritten in FIFO fashion, as + * needed. However, note that, if calling the function results in an + * overflow, the value of the ring buffer's tail pointer may be + * different than it was before the function was called. + */ +void * +ringbuf_memcpy_into(ringbuf_t dst, const void *src, size_t count); + +/* + * This convenience function calls read(2) on the file descriptor fd, + * using the ring buffer rb as the destination buffer for the read, + * and returns the value returned by read(2). It will only call + * read(2) once, and may return a short count. + * + * It is possible to read more data from the file descriptor than is + * available in the buffer; i.e., it's possible to overflow the ring + * buffer using this function. When an overflow occurs, the state of + * the ring buffer is guaranteed to be consistent, including the head + * and tail pointers: old data will simply be overwritten in FIFO + * fashion, as needed. However, note that, if calling the function + * results in an overflow, the value of the ring buffer's tail pointer + * may be different than it was before the function was called. + */ +ssize_t +ringbuf_read(int fd, ringbuf_t rb, size_t count); + +/* + * Copy n bytes from the ring buffer src, starting from its tail + * pointer, into a contiguous memory area dst. Returns the value of + * src's tail pointer after the copy is finished. + * + * Note that this copy is destructive with respect to the ring buffer: + * the n bytes copied from the ring buffer are no longer available in + * the ring buffer after the copy is complete, and the ring buffer + * will have n more free bytes than it did before the function was + * called. + * + * This function will *not* allow the ring buffer to underflow. If + * count is greater than the number of bytes used in the ring buffer, + * no bytes are copied, and the function will return 0. + */ +void * +ringbuf_memcpy_from(void *dst, ringbuf_t src, size_t count); + +/* + * This convenience function calls write(2) on the file descriptor fd, + * using the ring buffer rb as the source buffer for writing (starting + * at the ring buffer's tail pointer), and returns the value returned + * by write(2). It will only call write(2) once, and may return a + * short count. + * + * Note that this copy is destructive with respect to the ring buffer: + * any bytes written from the ring buffer to the file descriptor are + * no longer available in the ring buffer after the copy is complete, + * and the ring buffer will have N more free bytes than it did before + * the function was called, where N is the value returned by the + * function (unless N is < 0, in which case an error occurred and no + * bytes were written). + * + * This function will *not* allow the ring buffer to underflow. If + * count is greater than the number of bytes used in the ring buffer, + * no bytes are written to the file descriptor, and the function will + * return 0. + */ +ssize_t +ringbuf_write(int fd, ringbuf_t rb, size_t count); + +/* + * Copy count bytes from ring buffer src, starting from its tail + * pointer, into ring buffer dst. Returns dst's new head pointer after + * the copy is finished. + * + * Note that this copy is destructive with respect to the ring buffer + * src: any bytes copied from src into dst are no longer available in + * src after the copy is complete, and src will have 'count' more free + * bytes than it did before the function was called. + * + * It is possible to copy more data from src than is available in dst; + * i.e., it's possible to overflow dst using this function. When an + * overflow occurs, the state of dst is guaranteed to be consistent, + * including the head and tail pointers; old data will simply be + * overwritten in FIFO fashion, as needed. However, note that, if + * calling the function results in an overflow, the value dst's tail + * pointer may be different than it was before the function was + * called. + * + * It is *not* possible to underflow src; if count is greater than the + * number of bytes used in src, no bytes are copied, and the function + * returns 0. + */ +void * +ringbuf_copy(ringbuf_t dst, ringbuf_t src, size_t count); + +#endif /* INCLUDED_RINGBUF_H */ diff --git a/plugins/alsa/time_utils.c b/plugins/alsa/time_utils.c new file mode 100644 index 0000000..6f22e9d --- /dev/null +++ b/plugins/alsa/time_utils.c @@ -0,0 +1,17 @@ +#include "time_utils.h" +#include "time.h" + +__thread uint64_t last = 0; + +uint64_t now_monotonic_usec() { + struct timespec now; + clock_gettime(CLOCK_MONOTONIC, &now); + return now.tv_sec*1000000+now.tv_nsec/1000; +} + +uint64_t ts() { + uint64_t now = now_monotonic_usec(); + uint64_t elapsed = now-last; + last = now; + return elapsed; +} diff --git a/plugins/alsa/time_utils.h b/plugins/alsa/time_utils.h new file mode 100644 index 0000000..ece4e17 --- /dev/null +++ b/plugins/alsa/time_utils.h @@ -0,0 +1,9 @@ +#ifndef __INC_TIME_H +#define __INC_TIME_H + +#include <stdint.h> + +extern uint64_t now_monotonic_usec(); +extern uint64_t ts(); + +#endif /* __INC_TIME_H */ |