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 e57730a..01c96f6 100644 (file)
--- a/odr/odr_mem.c
+++ b/odr/odr_mem.c
@@ -4,7 +4,14 @@
  * Sebastian Hammer, Adam Dickmeiss
  *
  * $Log: odr_mem.c,v $
- * Revision 1.2  1995-03-17 10:17:52  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
@@ -15,6 +22,9 @@
 
 #include <stdlib.h>
 #include <odr.h>
+#include <dmalloc.h>
+
+/* ------------------------ NIBBLE MEMORY ---------------------- */
 
 #define ODR_MEM_CHUNK (10*1024)
 
@@ -26,7 +36,7 @@ typedef struct odr_memblock
     struct odr_memblock *next;
 } odr_memblock;
 
-static odr_memblock *freelist = 0;
+static odr_memblock *freelist = 0; /* global freelist */
 
 static void free_block(odr_memblock *p)
 {
@@ -34,6 +44,9 @@ static void free_block(odr_memblock *p)
     freelist = p;
 }
 
+/*
+ * acquire a block with a minimum of size free bytes.
+ */
 static odr_memblock *get_block(int size)
 {
     odr_memblock *r, *l;
@@ -53,15 +66,18 @@ static odr_memblock *get_block(int size)
        if (get < size)
            get = size;
        if (!(r = malloc(sizeof(*r))))
-           return 0;
+           abort();
        if (!(r->buf = malloc(r->size = get)))
-           return 0;
+           abort();
     }
     r->top = 0;
     return r;
 }
 
-void odr_release_mem(odr_memblock *p)
+/*
+ * Return p to the global freelist.
+ */
+void odr_release_mem(ODR_MEM p)
 {
     odr_memblock *t;
 
@@ -73,6 +89,17 @@ void odr_release_mem(odr_memblock *p)
     }
 }
 
+/*
+ * 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;
@@ -80,16 +107,68 @@ void *odr_malloc(ODR o, int size)
 
     if (!p || p->size - p->top < size)
        if (!(p = get_block(size)))
-       {
-           o->error = OMEMORY;
-           return 0;
-       }
+           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;
+}
+
+int odr_seek(ODR o, int whence, int offset)
+{
+    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;
+}