X-Git-Url: https://git.distorted.org.uk/~mdw/mLib/blobdiff_plain/b64eb60f6c1fdb12f3922e04913e137199838807..bca75e8d0ad7ce51192de3ef053ec63d0c79cfaa:/struct/buf.c

diff --git a/struct/buf.c b/struct/buf.c
index 11b1425..5d1fc27 100644
--- a/struct/buf.c
+++ b/struct/buf.c
@@ -53,6 +53,52 @@ void buf_init(buf *b, void *p, size_t sz)
   b->f = 0;
 }
 
+/* --- @dbuf_create@ --- *
+ *
+ * Arguments:	@dbuf *db@ = pointer to a dynamic buffer block
+ *
+ * Returns:	---
+ *
+ * Use:		Initializes a dynamic buffer.  The buffer is initially empty,
+ *		and ready for writing.
+ */
+
+void dbuf_create(dbuf *db)
+{
+  db->_b.base = db->_b.p = db->_b.limit = 0; db->_b.f = BF_ALLOC | BF_WRITE;
+  db->a = &arena_stdlib; db->sz = 0;
+}
+
+/* --- @dbuf_reset@ --- *
+ *
+ * Arguments:	@dbuf *db@ = pointer to a buffer block
+ *
+ * Returns:	---
+ *
+ * Use:		Resets a buffer so that it can be written again.
+ */
+
+void dbuf_reset(dbuf *db)
+{
+  db->_b.p = db->_b.base; db->_b.limit = db->_b.base + db->sz;
+  db->_b.f = (db->_b.f&~BF_BROKEN) | BF_WRITE;
+}
+
+/* --- @dbuf_destroy@ --- *
+ *
+ * Arguments:	@dbuf *db@ = pointer to a buffer block
+ *
+ * Returns:	---
+ *
+ * Use:		Release all of the resources held by a dynamic buffer.
+ */
+
+void dbuf_destroy(dbuf *db)
+{
+  if (db->_b.base) x_free(db->a, db->_b.base);
+  dbuf_create(db);
+}
+
 /* --- @buf_break@ --- *
  *
  * Arguments:	@buf *b@ = pointer to a buffer block
@@ -76,8 +122,8 @@ int buf_break(buf *b) { b->f |= BF_BROKEN; return (-1); }
 
 void buf_flip(buf *b)
 {
-  b->limit = b->p;
-  b->p = b->base;
+  b->limit = b->p; b->p = b->base;
+  b->f &= ~BF_WRITE;
 }
 
 /* --- @buf_ensure@ --- *
@@ -92,6 +138,39 @@ void buf_flip(buf *b)
 
 int buf_ensure(buf *b, size_t sz) { return (BENSURE(b, sz)); }
 
+/* --- @buf_tryextend@ --- *
+ *
+ * Arguments:	@buf *b@ = pointer to a buffer block
+ *		@size_t sz@ = size of data wanted
+ *
+ * Returns:	Zero if it worked, nonzero if the buffer won't grow.
+ *
+ * Use:		Extend the buffer so that at least @sz@ bytes are available.
+ *		This only works if the buffer is allocated.
+ */
+
+int buf_tryextend(buf *b, size_t sz)
+{
+  dbuf *db;
+  size_t newsz, len;
+
+  if (~b->f&(BF_ALLOC | BF_WRITE))
+    { b->f |= BF_BROKEN; return (-1); }
+  db = (dbuf *)b;
+  len = BLEN(&db->_b); sz += len;
+  if (db->sz >= sz)
+    newsz = db->sz;
+  else {
+    newsz = db->sz ? 2*db->sz : 64;
+    while (newsz < sz) { assert(newsz < ((size_t)-1)/2); newsz *= 2; }
+    if (!db->_b.base) db->_b.base = x_alloc(db->a, newsz);
+    else db->_b.base = x_realloc(db->a, db->_b.base, newsz, db->sz);
+    db->_b.p = db->_b.base + len; db->sz = newsz;
+  }
+  db->_b.limit = db->_b.base + newsz;
+  return (0);
+}
+
 /* --- @buf_get@ --- *
  *
  * Arguments:	@buf *b@ = pointer to a buffer block
@@ -315,6 +394,44 @@ void *buf_getmemz(buf *b, size_t *nn)
   return (buf_get(b, *nn));
 }
 
+#ifndef HAVE_UINT64
+
+static void *getmem_k64(buf *b, size_t *nn_out, kludge64 k)
+{
+  kludge64 szmax;
+  size_t n;
+
+  ASSIGN64(szmax, (size_t)-1);
+  if (CMP64(k, >, szmax)) { buf_break(b); return (-1); }
+  n = GET64(size_t, k); *nn_out = n; return (buf_get(b, n));
+}
+
+void *buf_getmem64(buf *b, size_t *nn)
+{
+  kludge64 k;
+
+  if (buf_getk64(b, &k)) return (-1);
+  return (getmem_k64(b, nn, k));
+}
+
+void *buf_getmem64b(buf *b, size_t *nn)
+{
+  kludge64 k;
+
+  if (buf_getk64b(b, &k)) return (-1);
+  return (getmem_k64(b, nn, k));
+}
+
+void *buf_getmem64l(buf *b, size_t *nn)
+{
+  kludge64 k;
+
+  if (buf_getk64l(b, &k)) return (-1);
+  return (getmem_k64(b, nn, k));
+}
+
+#endif
+
 /* --- @buf_putmem{8,{16,24,32,64}{,l,b},z} --- *
  *
  * Arguments:	@buf *b@ = pointer to a buffer block
@@ -340,6 +457,34 @@ void *buf_getmemz(buf *b, size_t *nn)
   }
 DOUINTCONV(BUF_PUTMEM_)
 
+#ifndef HAVE_UINT64
+
+void *buf_putmem64(buf *b, const void *p, size_t n)
+{
+  kludge64 k;
+
+  ASSIGN64(k, n); if (buf_putk64(b, k) || buf_put(b, p, n)) return (-1);
+  return (0);
+}
+
+void *buf_putmem64b(buf *b, const void *p, size_t n)
+{
+  kludge64 k;
+
+  ASSIGN64(k, n); if (buf_putk64b(b, k) || buf_put(b, p, n)) return (-1);
+  return (0);
+}
+
+void *buf_putmem64l(buf *b, const void *p, size_t n)
+{
+  kludge64 k;
+
+  ASSIGN64(k, n); if (buf_putk64l(b, k) || buf_put(b, p, n)) return (-1);
+  return (0);
+}
+
+#endif
+
 int buf_putmemz(buf *b, const void *p, size_t n)
 {
   octet *q;