Make sure we don't get stuck when prebuf is too high

If prebuf is greater than tlength minus minreq we might end up waiting
for the buffer to fill up further however without ever asking for more
data from the client since less minreq bytes might be missing.

This fixes bug #440

1 files changed, 23 insertions, 29 deletions

diff --git a/src/pulsecore/memblockq.c b/src/pulsecore/memblockq.c
index d12d13a8..77f9efc9 100644
--- a/src/pulsecore/memblockq.c
+++ b/src/pulsecore/memblockq.c
@@ -90,8 +90,8 @@ pa_memblockq* pa_memblockq_new(
 
     pa_memblockq_set_maxlength(bq, maxlength);
     pa_memblockq_set_tlength(bq, tlength);
-    pa_memblockq_set_prebuf(bq, prebuf);
     pa_memblockq_set_minreq(bq, minreq);
+    pa_memblockq_set_prebuf(bq, prebuf);
     pa_memblockq_set_maxrewind(bq, maxrewind);
 
     pa_log_debug("memblockq sanitized: maxlength=%lu, tlength=%lu, base=%lu, prebuf=%lu, minreq=%lu maxrewind=%lu",
@@ -784,16 +784,13 @@ void pa_memblockq_set_maxlength(pa_memblockq *bq, size_t maxlength) {
 
     if (bq->tlength > bq->maxlength)
         pa_memblockq_set_tlength(bq, bq->maxlength);
-
-    if (bq->prebuf > bq->maxlength)
-        pa_memblockq_set_prebuf(bq, bq->maxlength);
 }
 
 void pa_memblockq_set_tlength(pa_memblockq *bq, size_t tlength) {
     size_t old_tlength;
     pa_assert(bq);
 
-    if (tlength <= 0)
+    if (tlength <= 0 || tlength == (size_t) -1)
         tlength = bq->maxlength;
 
     old_tlength = bq->tlength;
@@ -802,49 +799,46 @@ void pa_memblockq_set_tlength(pa_memblockq *bq, size_t tlength) {
     if (bq->tlength > bq->maxlength)
         bq->tlength = bq->maxlength;
 
-    if (bq->prebuf > bq->tlength)
-        pa_memblockq_set_prebuf(bq, bq->tlength);
-
     if (bq->minreq > bq->tlength)
         pa_memblockq_set_minreq(bq, bq->tlength);
 
+    if (bq->prebuf > bq->tlength+bq->base-bq->minreq)
+        pa_memblockq_set_prebuf(bq, bq->tlength+bq->base-bq->minreq);
+
     bq->missing += (int64_t) bq->tlength - (int64_t) old_tlength;
 }
 
+void pa_memblockq_set_minreq(pa_memblockq *bq, size_t minreq) {
+    pa_assert(bq);
+
+    bq->minreq = (minreq/bq->base)*bq->base;
+
+    if (bq->minreq > bq->tlength)
+        bq->minreq = bq->tlength;
+
+    if (bq->minreq < bq->base)
+        bq->minreq = bq->base;
+
+    if (bq->prebuf > bq->tlength+bq->base-bq->minreq)
+        pa_memblockq_set_prebuf(bq, bq->tlength+bq->base-bq->minreq);
+}
+
 void pa_memblockq_set_prebuf(pa_memblockq *bq, size_t prebuf) {
     pa_assert(bq);
 
     if (prebuf == (size_t) -1)
-        prebuf = bq->tlength;
+        prebuf = bq->tlength+bq->base-bq->minreq;
 
     bq->prebuf = ((prebuf+bq->base-1)/bq->base)*bq->base;
 
     if (prebuf > 0 && bq->prebuf < bq->base)
         bq->prebuf = bq->base;
 
-    if (bq->prebuf > bq->tlength)
-        bq->prebuf = bq->tlength;
+    if (bq->prebuf > bq->tlength+bq->base-bq->minreq)
+        bq->prebuf = bq->tlength+bq->base-bq->minreq;
 
     if (bq->prebuf <= 0 || pa_memblockq_get_length(bq) >= bq->prebuf)
         bq->in_prebuf = FALSE;
-
-    if (bq->minreq > bq->prebuf)
-        pa_memblockq_set_minreq(bq, bq->prebuf);
-}
-
-void pa_memblockq_set_minreq(pa_memblockq *bq, size_t minreq) {
-    pa_assert(bq);
-
-    bq->minreq = (minreq/bq->base)*bq->base;
-
-    if (bq->minreq > bq->tlength)
-        bq->minreq = bq->tlength;
-
-    if (bq->minreq > bq->prebuf)
-        bq->minreq = bq->prebuf;
-
-    if (bq->minreq < bq->base)
-        bq->minreq = bq->base;
 }
 
 void pa_memblockq_set_maxrewind(pa_memblockq *bq, size_t maxrewind) {