1 files changed, 188 insertions, 0 deletions
diff --git a/polyp/mcalign.c b/polyp/mcalign.c
new file mode 100644
index 000000000..0b7f0db01
--- /dev/null
+++ b/polyp/mcalign.c
@@ -0,0 +1,188 @@
+/* $Id$ */
+
+/***
+  This file is part of polypaudio.
+ 
+  polypaudio is free software; you can redistribute it and/or modify
+  it under the terms of the GNU Lesser General Public License as
+  published by the Free Software Foundation; either version 2.1 of the
+  License, or (at your option) any later version.
+ 
+  polypaudio is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+ 
+  You should have received a copy of the GNU Lesser General Public
+  License along with polypaudio; if not, write to the Free Software
+  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+  USA.
+***/
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <assert.h>
+#include <string.h>
+
+#include "mcalign.h"
+#include "xmalloc.h"
+
+struct pa_mcalign {
+    size_t base;
+    struct pa_memchunk leftover, current;
+    struct pa_memblock_stat *memblock_stat;
+};
+
+struct pa_mcalign *pa_mcalign_new(size_t base, struct pa_memblock_stat *s) {
+    struct pa_mcalign *m;
+    assert(base);
+
+    m = pa_xmalloc(sizeof(struct pa_mcalign));
+    m->base = base;
+    pa_memchunk_reset(&m->leftover);
+    pa_memchunk_reset(&m->current);
+    m->memblock_stat = s;
+    
+    return m;
+}
+
+void pa_mcalign_free(struct pa_mcalign *m) {
+    assert(m);
+
+    if (m->leftover.memblock)
+        pa_memblock_unref(m->leftover.memblock);
+
+    if (m->current.memblock)
+        pa_memblock_unref(m->current.memblock);
+    
+    pa_xfree(m);
+}
+
+void pa_mcalign_push(struct pa_mcalign *m, const struct pa_memchunk *c) {
+    assert(m && c && c->memblock && c->length);
+    
+    /* Append to the leftover memory block */
+    if (m->leftover.memblock) {
+        assert(!m->current.memblock);
+        
+        /* Try to merge */
+        if (m->leftover.memblock == c->memblock &&
+            m->leftover.index + m->leftover.length == c->index) {
+
+            /* Merge */
+            m->leftover.length += c->length;
+
+            /* If the new chunk is larger than m->base, move it to current */
+            if (m->leftover.length >= m->base) {
+                m->current = m->leftover;
+                pa_memchunk_reset(&m->leftover);
+            } 
+
+        } else {
+            size_t l;
+
+            /* We have to copy */
+            assert(m->leftover.length < m->base);
+            l = m->base - m->leftover.length;
+            
+            if (l > c->length)
+                l = c->length;
+
+            /* Can we use the current block? */
+            pa_memchunk_make_writable(&m->leftover, m->memblock_stat, m->base);
+
+            memcpy((uint8_t*) m->leftover.memblock->data + m->leftover.index + m->leftover.length, (uint8_t*) c->memblock->data + c->index, l);
+            m->leftover.length += l;
+
+            assert(m->leftover.length <= m->base && m->leftover.length <= m->leftover.memblock->length);
+
+            if (c->length > l) {
+                /* Save the remainder of the memory block */
+                m->current = *c;
+                m->current.index += l;
+                m->current.length -= l;
+                pa_memblock_ref(m->current.memblock);
+            }
+        }
+    } else {
+        assert(!m->leftover.memblock && !m->current.memblock);
+
+        /* Nothing to merge or copy, just store it */
+        
+        if (c->length >= m->base)
+            m->current = *c;
+        else
+            m->leftover = *c;
+
+        pa_memblock_ref(c->memblock);
+    }
+}
+
+int pa_mcalign_pop(struct pa_mcalign *m, struct pa_memchunk *c) {
+    assert(m && c);
+
+    /* First test if there's a leftover memory block available */
+    if (m->leftover.memblock) {
+        assert(m->leftover.length > 0 && m->leftover.length <= m->base);
+
+        /* The leftover memory block is not yet complete */
+        if (m->leftover.length < m->base)
+            return -1;
+
+        /* Return the leftover memory block */
+        *c = m->leftover;
+        pa_memchunk_reset(&m->leftover);
+
+        /* If the current memblock is too small move it the leftover */
+        if (m->current.memblock && m->current.length < m->base) {
+            m->leftover = m->current;
+            pa_memchunk_reset(&m->current);
+        }
+        
+        return 0;
+    }
+
+    /* Now let's see if there is other data available */
+    if (m->current.memblock) {
+        size_t l;
+        assert(m->current.length >= m->base);
+
+        /* The length of the returned memory block */
+        l = m->current.length;
+        l /= m->base;
+        l *= m->base;
+        assert(l > 0);
+
+        /* Prepare the returned block */
+        *c = m->current;
+        pa_memblock_ref(c->memblock);
+        c->length = l;
+
+        /* Drop that from the current memory block */
+        assert(l <= m->current.length);
+        m->current.index += l;
+        m->current.length -= l;
+
+        /* In case the whole block was dropped ... */
+        if (m->current.length == 0)
+            pa_memblock_unref(m->current.memblock);
+        else {
+            /* Move the raimainder to leftover */
+            assert(m->current.length < m->base && !m->leftover.memblock);
+
+            m->leftover = m->current;
+        }
+
+        pa_memchunk_reset(&m->current);
+            
+        return 0;
+    }
+
+    /* There's simply nothing */
+    return -1;
+    
+}