New WRBUF utility: wrbuf_insert

diff --git a/include/yaz/wrbuf.h b/include/yaz/wrbuf.h
index 1296538..1b11e2f 100644 (file)
--- a/include/yaz/wrbuf.h
+++ b/include/yaz/wrbuf.h
@@ -63,13 +63,21 @@ YAZ_EXPORT void wrbuf_destroy(WRBUF b);
  */
 YAZ_EXPORT void wrbuf_rewind(WRBUF b);
 
-/** \brief append constant size buffer to WRBU
+/** \brief append constant size buffer to WRBUF
     \param b WRBUF
     \param buf buffer
     \param size size of buffer
  */
 YAZ_EXPORT void wrbuf_write(WRBUF b, const char *buf, size_t size);
 
+/** \brief inserts buffer into WRBUF at some position
+    \param b WRBUF
+    \param pos position (0=beginning)
+    \param buf buffer
+    \param size size of buffer
+ */
+YAZ_EXPORT void wrbuf_insert(WRBUF b, size_t pos, const char *buf, size_t size);
+
 /** \brief appends C-string to WRBUF
     \param b WRBUF
     \param buf C-string (0-terminated)

diff --git a/src/wrbuf.c b/src/wrbuf.c
index 67de45e..13793ed 100644 (file)
--- a/src/wrbuf.c
+++ b/src/wrbuf.c
@@ -74,6 +74,17 @@ void wrbuf_write(WRBUF b, const char *buf, size_t size)
     b->pos += size;
 }
 
+void wrbuf_insert(WRBUF b, size_t pos, const char *buf, size_t size)
+{
+    if (size <= 0 || pos > b->pos)
+        return;
+    if (b->pos + size >= b->size)
+        wrbuf_grow(b, size);
+    memmove(b->buf + pos + size, b->buf + pos, b->pos - pos);
+    memcpy(b->buf + pos, buf, size);
+    b->pos += size;
+}
+
 void wrbuf_puts(WRBUF b, const char *buf)
 {
     wrbuf_write(b, buf, strlen(buf));