From e5d1c949ac4c15e353160a5006ac3a8cea14dac5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=A9r=C3=A9my=20Zurcher?= <jeremy@asynk.ch>
Date: Tue, 12 Jan 2010 13:14:19 +0100
Subject: add _read_size and _write_size to lf_ringbuffer

---
 lf_ringbuffer.c | 28 +++++++++++++++++++++++++++-
 lf_ringbuffer.h |  6 ++++++
 2 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/lf_ringbuffer.c b/lf_ringbuffer.c
index facf055..48b848e 100644
--- a/lf_ringbuffer.c
+++ b/lf_ringbuffer.c
@@ -83,7 +83,7 @@ lf_ringbuffer_t* lf_ringbuffer_create( size_t n_buf ) {
     return r;
 }
 
-/* destroy an lf_ringbuffer strcture */
+/* destroy an lf_ringbuffer struct */
 void lf_ringbuffer_destroy( lf_ringbuffer_t *r ) {
     free(r->buffer);
     free(r);
@@ -92,6 +92,32 @@ void lf_ringbuffer_destroy( lf_ringbuffer_t *r ) {
 /* return 1 if is empty */
 int lf_ringbuffer_empty( lf_ringbuffer_t *r ) { return (r->indexes>>16)==USHORTMAX; }
 
+/* return count of filled buffers */
+size_t lf_ringbuffer_read_size( lf_ringbuffer_t *r ) {
+    unsigned int write_to, read_from;
+    read_from = (r->indexes)>>16;
+    if(read_from==USHORTMAX) return 0;
+    write_to = (r->indexes)&0xffff;
+    if(write_to>read_from) {
+        return write_to-read_from;
+    } else {
+        return r->n_buf-read_from+write_to;
+    }
+}
+
+/* return count of available buffers */
+size_t lf_ringbuffer_write_size( lf_ringbuffer_t *r ) {
+    unsigned int write_to, read_from;
+    read_from = (r->indexes)>>16;
+    if(read_from==USHORTMAX) return r->n_buf;
+    write_to = (r->indexes)&0xffff;
+    if(write_to>read_from) {
+        return r->n_buf-write_to+read_from;
+    } else {
+        return read_from-write_to;
+    }
+}
+
 /* write data into the ring buffer */
 int lf_ringbuffer_write( lf_ringbuffer_t *r, void *data, int flags ) {
     unsigned int current, next;
diff --git a/lf_ringbuffer.h b/lf_ringbuffer.h
index a5dc0cb..feb5f17 100644
--- a/lf_ringbuffer.h
+++ b/lf_ringbuffer.h
@@ -54,6 +54,12 @@ void lf_ringbuffer_destroy( lf_ringbuffer_t *r );
 /* return 1 if is empty */
 int lf_ringbuffer_empty( lf_ringbuffer_t *r );
 
+/* return the count of filled buffers */
+size_t lf_ringbuffer_read_size( lf_ringbuffer_t *r );
+
+/* return the count of available buffers */
+size_t lf_ringbuffer_write_size( lf_ringbuffer_t *r );
+
 /* write data into the ring buffer
  * return 0 on success
  * return -1 if IS_NOT_BLOCKING and buffer is full
-- 
cgit v1.1-2-g2b99