[#101] Improve ringbuffer handling

Author: jesperpedersen

doc/CMakeLists.txt

@@ -118,7 +118,10 @@ if (DOCS)
         ${DOXYGEN_VERSION} STREQUAL "1.13.0" OR
         ${DOXYGEN_VERSION} STREQUAL "1.13.1" OR
         ${DOXYGEN_VERSION} STREQUAL "1.13.2" OR
-        ${DOXYGEN_VERSION} STREQUAL "1.14.0")
+        ${DOXYGEN_VERSION} STREQUAL "1.14.0" OR
+        ${DOXYGEN_VERSION} STREQUAL "1.15.0" OR
+        ${DOXYGEN_VERSION} STREQUAL "1.16.0" OR
+        ${DOXYGEN_VERSION} STREQUAL "1.16.1")
       add_custom_command(
         TARGET api
         COMMAND ${DOXYGEN_EXECUTABLE} -q ${DOXYFILE_OUT}

src/include/ringbuffer.h

@@ -28,6 +28,9 @@ extern "C" {
 #define HRMP_RINGBUFFER_MIN_BYTES (4u * 1024u * 1024u)
 #define HRMP_RINGBUFFER_MAX_BYTES (256u * 1024u * 1024u)
 
+/** @struct ringbuffer
+ * Ringbuffer storage.
+ */
 struct ringbuffer
 {
    uint8_t *buf; /**< The buffer */

src/libhrmp/files.c

@@ -1063,6 +1063,7 @@ get_metadata_dsf(char* filename, struct file_metadata** file_metadata)
 
    hrmp_read_le_u32(f);             /* DATA */
    data_size = hrmp_read_le_u64(f); /* data_size */
+   long data_offset = ftell(f);
 
    if (srate % 16)
    {
@@ -1087,7 +1088,33 @@ get_metadata_dsf(char* filename, struct file_metadata** file_metadata)
    fm->total_samples = samples;
    fm->duration = (double)((double)samples / srate);
    fm->block_size = block_size;
-   fm->data_size = data_size;
+   uint64_t max_bytes = data_size;
+   if (fm->file_size > 0 && data_offset > 0 && (uint64_t)data_offset < fm->file_size)
+   {
+      uint64_t avail = fm->file_size - (uint64_t)data_offset;
+      if (metadata_chunk != 0 && metadata_chunk > (uint64_t)data_offset && metadata_chunk <= fm->file_size)
+      {
+         avail = metadata_chunk - (uint64_t)data_offset;
+      }
+      if (avail < max_bytes)
+      {
+         max_bytes = avail;
+      }
+   }
+
+   if (samples > 0 && channel_number > 0)
+   {
+      uint64_t expected_bytes = (samples * (uint64_t)channel_number + 7u) / 8u;
+      fm->data_size = expected_bytes;
+      if (max_bytes < fm->data_size)
+      {
+         fm->data_size = max_bytes;
+      }
+   }
+   else
+   {
+      fm->data_size = max_bytes;
+   }
 
    if (metadata_chunk != 0)
    {

src/libhrmp/mkv.c

@@ -59,6 +59,60 @@ ebml_reader_init(EbmlReader* r, FILE* fp, struct ringbuffer* rb, uint64_t file_s
    }
 }
 
+static void
+mkv_prefill_ringbuffer(EbmlReader* r)
+{
+   if (!r || !r->rb || !r->fp)
+   {
+      return;
+   }
+
+   size_t target = r->rb->max;
+   if (r->file_size > 0)
+   {
+      off_t pos = ftello(r->fp);
+      if (pos >= 0 && (uint64_t)pos <= r->file_size)
+      {
+         uint64_t remaining = r->file_size - (uint64_t)pos;
+         if (remaining < target)
+         {
+            target = (size_t)remaining;
+         }
+      }
+   }
+   if (target < r->rb->min)
+   {
+      target = r->rb->min;
+   }
+
+   size_t cur = hrmp_ringbuffer_size(r->rb);
+   if (target > cur)
+   {
+      (void)hrmp_ringbuffer_ensure_write(r->rb, target - cur);
+   }
+
+   while (hrmp_ringbuffer_size(r->rb) < hrmp_ringbuffer_capacity(r->rb))
+   {
+      void* wp = NULL;
+      size_t span = hrmp_ringbuffer_get_write_span(r->rb, &wp);
+      if (span == 0)
+      {
+         break;
+      }
+
+      size_t got = fread(wp, 1, span, r->fp);
+      if (got == 0)
+      {
+         break;
+      }
+
+      if (hrmp_ringbuffer_produce(r->rb, got))
+      {
+         break;
+      }
+   }
+}
+
 static uint64_t
 ebml_tell(EbmlReader* r)
 {
@@ -113,6 +167,7 @@ ebml_read(EbmlReader* r, void* dst, size_t size)
    }
    else
    {
+      mkv_prefill_ringbuffer(r);
       uint8_t* out = (uint8_t*)dst;
       while (n < size)
       {
@@ -124,6 +179,7 @@ ebml_read(EbmlReader* r, void* dst, size_t size)
             memcpy(out + n, rp, take);
             hrmp_ringbuffer_consume(r->rb, take);
             n += take;
+            mkv_prefill_ringbuffer(r);
             continue;
          }