forgot to add memchunk.[ch]

git-svn-id: file:///home/lennart/svn/public/pulseaudio/trunk@46 fefdeb5f-60dc-0310-8127-8f9354f1896f

2 files changed, 144 insertions, 0 deletions

diff --git a/src/memchunk.c b/src/memchunk.c
new file mode 100644
index 00000000..faee4508
--- /dev/null
+++ b/src/memchunk.c
@@ -0,0 +1,124 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <assert.h>
+#include <string.h>
+
+#include "memchunk.h"
+
+void memchunk_make_writable(struct memchunk *c) {
+    struct memblock *n;
+    assert(c && c->memblock && c->memblock->ref >= 1);
+
+    if (c->memblock->ref == 1)
+        return;
+    
+    n = memblock_new(c->length);
+    assert(n);
+    memcpy(n->data, c->memblock->data+c->index, c->length);
+    memblock_unref(c->memblock);
+    c->memblock = n;
+    c->index = 0;
+}
+
+
+struct mcalign {
+    size_t base;
+    struct memchunk chunk;
+    uint8_t *buffer;
+    size_t buffer_fill;
+};
+
+struct mcalign *mcalign_new(size_t base) {
+    struct mcalign *m;
+    assert(base);
+
+    m = malloc(sizeof(struct mcalign));
+    assert(m);
+    m->base = base;
+    m->chunk.memblock = NULL;
+    m->chunk.length = m->chunk.index = 0;
+    m->buffer = NULL;
+    m->buffer_fill = 0;
+    return m;
+}
+
+void mcalign_free(struct mcalign *m) {
+    assert(m);
+
+    free(m->buffer);
+    
+    if (m->chunk.memblock)
+        memblock_unref(m->chunk.memblock);
+    
+    free(m);
+}
+
+void mcalign_push(struct mcalign *m, const struct memchunk *c) {
+    assert(m && c && !m->chunk.memblock && c->memblock && c->length);
+
+    m->chunk = *c;
+    memblock_ref(m->chunk.memblock);
+}
+
+int mcalign_pop(struct mcalign *m, struct memchunk *c) {
+    assert(m && c && m->base > m->buffer_fill);
+    int ret;
+
+    if (!m->chunk.memblock)
+        return -1;
+
+    if (m->buffer_fill) {
+        size_t l = m->base - m->buffer_fill;
+        if (l > m->chunk.length)
+            l = m->chunk.length;
+        assert(m->buffer && l);
+
+        memcpy(m->buffer + m->buffer_fill, m->chunk.memblock->data + m->chunk.index, l);
+        m->buffer_fill += l;
+        m->chunk.index += l;
+        m->chunk.length -= l;
+
+        if (m->chunk.length == 0) {
+            m->chunk.length = m->chunk.index = 0;
+            memblock_unref(m->chunk.memblock);
+            m->chunk.memblock = NULL;
+        }
+
+        assert(m->buffer_fill <= m->base);
+        if (m->buffer_fill == m->base) {
+            c->memblock = memblock_new_dynamic(m->buffer, m->base);
+            assert(c->memblock);
+            c->index = 0;
+            c->length = m->base;
+            m->buffer = NULL;
+            m->buffer_fill = 0;
+
+            return 0;
+        }
+
+        return -1;
+    }
+
+    m->buffer_fill = m->chunk.length % m->base;
+
+    if (m->buffer_fill) {
+        assert(!m->buffer);
+        m->buffer = malloc(m->base);
+        assert(m->buffer);
+        m->chunk.length -= m->buffer_fill;
+        memcpy(m->buffer, m->chunk.memblock->data + m->chunk.index + m->chunk.length, m->buffer_fill);
+    }
+
+    if (m->chunk.length) {
+        *c = m->chunk;
+        memblock_ref(c->memblock);
+        ret = 0;
+    } else
+        ret = -1;
+    
+    m->chunk.length = m->chunk.index = 0;
+    memblock_unref(m->chunk.memblock);
+    m->chunk.memblock = NULL;
+
+    return ret;
+}
diff --git a/src/memchunk.h b/src/memchunk.h
new file mode 100644
index 00000000..d395cf2c
--- /dev/null
+++ b/src/memchunk.h
@@ -0,0 +1,20 @@
+#ifndef foomemchunkhfoo
+#define foomemchunkhfoo
+
+#include "memblock.h"
+
+struct memchunk {
+    struct memblock *memblock;
+    size_t index, length;
+};
+
+void memchunk_make_writable(struct memchunk *c);
+
+struct mcalign;
+
+struct mcalign *mcalign_new(size_t base);
+void mcalign_free(struct mcalign *m);
+void mcalign_push(struct mcalign *m, const struct memchunk *c);
+int mcalign_pop(struct mcalign *m, struct memchunk *c);
+
+#endif