More work on memory management.

[yaz-moved-to-github.git] / odr / odr_mem.c

diff --git a/odr/odr_mem.c b/odr/odr_mem.c
index 4d6bf6d..01c96f6 100644 (file)
--- a/odr/odr_mem.c
+++ b/odr/odr_mem.c
@@ -4,18 +4,171 @@
  * Sebastian Hammer, Adam Dickmeiss
  *
  * $Log: odr_mem.c,v $
- * Revision 1.1  1995-03-14 10:27:40  quinn
+ * Revision 1.4  1995-05-15 11:56:09  quinn
+ * More work on memory management.
+ *
+ * Revision 1.3  1995/04/18  08:15:21  quinn
+ * Added dynamic memory allocation on encoding (whew). Code is now somewhat
+ * neater. We'll make the same change for decoding one day.
+ *
+ * Revision 1.2  1995/03/17  10:17:52  quinn
+ * Added memory management.
+ *
+ * Revision 1.1  1995/03/14  10:27:40  quinn
  * Modified makefile to use common lib
  * Beginning to add memory management to odr
  *
- *
  */
 
 #include <stdlib.h>
-
 #include <odr.h>
+#include <dmalloc.h>
+
+/* ------------------------ NIBBLE MEMORY ---------------------- */
+
+#define ODR_MEM_CHUNK (10*1024)
+
+typedef struct odr_memblock
+{
+    char *buf;
+    int size;
+    int top;
+    struct odr_memblock *next;
+} odr_memblock;
+
+static odr_memblock *freelist = 0; /* global freelist */
+
+static void free_block(odr_memblock *p)
+{
+    p->next = freelist;
+    freelist = p;
+}
+
+/*
+ * acquire a block with a minimum of size free bytes.
+ */
+static odr_memblock *get_block(int size)
+{
+    odr_memblock *r, *l;
+
+    for (r = freelist, l = 0; r; l = r, r = r->next)
+       if (r->size >= size)
+           break;
+    if (r)
+       if (l)
+           l->next = r->next;
+       else
+           freelist = r->next;
+    else
+    {
+       int get = ODR_MEM_CHUNK;
+
+       if (get < size)
+           get = size;
+       if (!(r = malloc(sizeof(*r))))
+           abort();
+       if (!(r->buf = malloc(r->size = get)))
+           abort();
+    }
+    r->top = 0;
+    return r;
+}
+
+/*
+ * Return p to the global freelist.
+ */
+void odr_release_mem(ODR_MEM p)
+{
+    odr_memblock *t;
+
+    while (p)
+    {
+       t = p;
+       p = p->next;
+       free_block(t);
+    }
+}
+
+/*
+ * Extract the memory control block from o.
+ */
+ODR_MEM odr_extract_mem(ODR o)
+{
+    ODR_MEM r = o->mem;
+
+    o->mem = 0;
+    return r;
+}
+
+void *odr_malloc(ODR o, int size)
+{
+    struct odr_memblock *p = o->mem;
+    char *r;
+
+    if (!p || p->size - p->top < size)
+       if (!(p = get_block(size)))
+           abort();
+       else
+       {
+           p->next = o->mem;
+           o->mem = p;
+       }
+    r = p->buf + p->top;
+    /* align size */
+    p->top += (size + (sizeof(long) - 1)) & ~(sizeof(long) - 1);
+    return r;
+}
+
+/* ---------- memory management for data encoding ----------*/
+
+
+int odr_grow_block(odr_ecblock *b, int min_bytes)
+{
+    int togrow;
+
+    if (!b->can_grow)
+       return -1;
+    if (!b->size)
+       togrow = 1024;
+    else
+       togrow = b->size;
+    if (togrow < min_bytes)
+       togrow = min_bytes;
+    if (b->size && !(b->buf = realloc(b->buf, b->size += togrow)))
+       abort();
+    else if (!b->size && !(b->buf = malloc(b->size = togrow)))
+       abort();
+#ifdef ODR_DEBUG
+    fprintf(stderr, "New size for encode_buffer: %d\n", b->size);
+#endif
+    return 0;
+}
+
+int odr_write(ODR o, unsigned char *buf, int bytes)
+{
+    if (o->ecb.pos + bytes >= o->ecb.size && odr_grow_block(&o->ecb, bytes))
+    {
+       o->error = OSPACE;
+       return -1;
+    }
+    memcpy(o->ecb.buf + o->ecb.pos, buf, bytes);
+    o->ecb.pos += bytes;
+    if (o->ecb.pos > o->ecb.top)
+       o->ecb.top = o->ecb.pos;
+    return 0;
+}
 
-char *odr_malloc(ODR o, int size)
+int odr_seek(ODR o, int whence, int offset)
 {
-    return malloc(size); /* REPLACE WITH NIBBLE MALLOC!! */
+    if (whence == ODR_S_CUR)
+       offset += o->ecb.pos;
+    else if (whence == ODR_S_END)
+       offset += o->ecb.top;
+    if (offset > o->ecb.size && odr_grow_block(&o->ecb, offset - o->ecb.size))
+    {
+       o->error = OSPACE;
+       return -1;
+    }
+    o->ecb.pos = offset;
+    return 0;
 }