resampler: Extend fit_buf() helper to copy leftover data to new buffer

the patch changes the interface of the (internal) fit_buf() function:
fit_buf() manages the memblock of the buf chunk, it reallocates the memblock
if the requested number of bytes ('len') if larger than the memblock's size ('size')
and optionally preserves 'copy' bytes

the code should be in line with the comment now

Signed-off-by: Peter Meerwald <pmeerw@pmeerw.net>

diff --git a/src/pulsecore/resampler.c b/src/pulsecore/resampler.c
index f0c663fb69facf74353f14ca2ecf0b731f564a74..4c788dcaca3d7d851a1c2f09f901d9f1aae3d555 100644 (file)
--- a/src/pulsecore/resampler.c
+++ b/src/pulsecore/resampler.c
@@ -1140,15 +1140,32 @@ static void calc_map_table(pa_resampler *r) {
     pa_init_remap(m);
 }
 
-static size_t fit_buf(pa_resampler *r, pa_memchunk *buf, size_t size) {
-    if (!buf->memblock || size < buf->length) {
-        size = buf->length;
-        if (buf->memblock)
+/* check if buf's memblock is large enough to hold 'len' bytes; create a
+ * new memblock if necessary and optionally preserve 'copy' data bytes */
+static void fit_buf(pa_resampler *r, pa_memchunk *buf, size_t len, size_t *size, size_t copy) {
+    pa_assert(size);
+
+    if (!buf->memblock || len > *size) {
+        pa_memblock *new_block = pa_memblock_new(r->mempool, len);
+
+        if (buf->memblock) {
+            if (copy > 0) {
+                void *src = pa_memblock_acquire(buf->memblock);
+                void *dst = pa_memblock_acquire(new_block);
+                pa_assert(copy <= len);
+                memcpy(dst, src, copy);
+                pa_memblock_release(new_block);
+                pa_memblock_release(buf->memblock);
+            }
+
             pa_memblock_unref(buf->memblock);
+        }
 
-        buf->memblock = pa_memblock_new(r->mempool, size);
+        buf->memblock = new_block;
+        *size = len;
     }
-    return size;
+
+    buf->length = len;
 }
 
 static pa_memchunk* convert_to_work_format(pa_resampler *r, pa_memchunk *input) {
@@ -1166,9 +1183,7 @@ static pa_memchunk* convert_to_work_format(pa_resampler *r, pa_memchunk *input)
         return input;
 
     n_samples = (unsigned) ((input->length / r->i_fz) * r->i_ss.channels);
-
-    r->to_work_format_buf.length = r->w_sz * n_samples;
-    r->to_work_format_buf_size = fit_buf(r, &r->to_work_format_buf, r->to_work_format_buf_size);
+    fit_buf(r, &r->to_work_format_buf, r->w_sz * n_samples, &r->to_work_format_buf_size, 0);
 
     src = pa_memblock_acquire_chunk(input);
     dst = pa_memblock_acquire(r->to_work_format_buf.memblock);
@@ -1212,24 +1227,7 @@ static pa_memchunk *remap_channels(pa_resampler *r, pa_memchunk *input) {
     }
 
     out_n_samples = out_n_frames * r->o_ss.channels;
-    r->remap_buf.length = out_n_samples * r->w_sz;
-
-    if (have_leftover) {
-        if (r->remap_buf_size < r->remap_buf.length) {
-            pa_memblock *new_block = pa_memblock_new(r->mempool, r->remap_buf.length);
-
-            src = pa_memblock_acquire(r->remap_buf.memblock);
-            dst = pa_memblock_acquire(new_block);
-            memcpy(dst, src, leftover_length);
-            pa_memblock_release(r->remap_buf.memblock);
-            pa_memblock_release(new_block);
-
-            pa_memblock_unref(r->remap_buf.memblock);
-            r->remap_buf.memblock = new_block;
-            r->remap_buf_size = r->remap_buf.length;
-        }
-    } else
-        r->remap_buf_size = fit_buf(r, &r->remap_buf, r->remap_buf_size);
+    fit_buf(r, &r->remap_buf, out_n_samples * r->w_sz, &r->remap_buf_size, leftover_length);
 
     src = pa_memblock_acquire_chunk(input);
     dst = (uint8_t *) pa_memblock_acquire(r->remap_buf.memblock) + leftover_length;
@@ -1257,8 +1255,7 @@ static void save_leftover(pa_resampler *r, void *buf, size_t len) {
     pa_assert(len > 0);
 
     /* Store the leftover data. */
-    r->leftover_buf->length = len;
-    *r->leftover_buf_size = fit_buf(r, r->leftover_buf, *r->leftover_buf_size);
+    fit_buf(r, r->leftover_buf, len, r->leftover_buf_size, 0);
     *r->have_leftover = true;
 
     dst = pa_memblock_acquire(r->leftover_buf->memblock);
@@ -1280,9 +1277,7 @@ static pa_memchunk *resample(pa_resampler *r, pa_memchunk *input) {
     in_n_frames = (unsigned) (input->length / r->w_fz);
 
     out_n_frames = ((in_n_frames*r->o_ss.rate)/r->i_ss.rate)+EXTRA_FRAMES;
-
-    r->resample_buf.length = r->w_fz * out_n_frames;
-    r->resample_buf_size = fit_buf(r, &r->resample_buf, r->resample_buf_size);
+    fit_buf(r, &r->resample_buf, r->w_fz * out_n_frames, &r->resample_buf_size, 0);
 
     leftover_n_frames = r->impl.resample(r, input, in_n_frames, &r->resample_buf, &out_n_frames);
 
@@ -1312,9 +1307,7 @@ static pa_memchunk *convert_from_work_format(pa_resampler *r, pa_memchunk *input
 
     n_samples = (unsigned) (input->length / r->w_sz);
     n_frames = n_samples / r->o_ss.channels;
-
-    r->from_work_format_buf.length = r->o_fz * n_frames;
-    r->from_work_format_buf_size = fit_buf(r, &r->from_work_format_buf, r->from_work_format_buf_size);
+    fit_buf(r, &r->from_work_format_buf, r->o_fz * n_frames, &r->from_work_format_buf_size, 0);
 
     src = pa_memblock_acquire_chunk(input);
     dst = pa_memblock_acquire(r->from_work_format_buf.memblock);