1 files changed, 87 insertions, 0 deletions

diff --git a/src/ot_iovec.c b/src/ot_iovec.c
new file mode 100644
index 0000000..328f160
--- /dev/null
+++ b/src/ot_iovec.c
@@ -0,0 +1,87 @@
+/* This software was written by Dirk Engling <erdgeist@erdgeist.org>
+   It is considered beerware. Prost. Skol. Cheers or whatever. */
+
+/* System */
+#include <stdlib.h>
+#include <sys/uio.h>
+
+/* Opentracker */
+#include "ot_iovec.h"
+
+void *iovec_new_chunk(size_t *iovec_entries, struct iovec **iovector, size_t new_alloc) {
+  void         *new_data;
+  size_t        new_entries = 1 + *iovec_entries;
+  struct iovec *new_vec     = realloc(*iovector, new_entries * sizeof(struct iovec));
+
+  if (!new_vec)
+    return NULL;
+
+  *iovector  = new_vec;
+
+  /* Only allocate after we have a place to store the pointer */
+  new_data = malloc(new_alloc);
+  if (!new_data)
+    return NULL;
+
+  new_vec[new_entries - 1].iov_base = new_data;
+  new_vec[new_entries - 1].iov_len  = new_alloc;
+
+  ++*iovec_entries;
+  return new_data;
+}
+
+void *iovec_append(size_t *iovec_entries, struct iovec **iovector, struct iovec *append_iovector) {
+  size_t        new_entries = *iovec_entries + 1;
+  struct iovec *new_vec     = realloc(*iovector, new_entries * sizeof(struct iovec));
+  if (!new_vec)
+    return NULL;
+
+  /* Take over data from appended iovec */
+  new_vec[*iovec_entries].iov_base = append_iovector->iov_base;
+  new_vec[*iovec_entries].iov_len  = append_iovector->iov_len;
+
+  append_iovector->iov_base        = NULL;
+  append_iovector->iov_len         = 0;
+
+  *iovector                        = new_vec;
+  *iovec_entries                   = new_entries;
+
+  return new_vec;
+}
+
+void iovec_free(size_t *iovec_entries, struct iovec **iovector) {
+  size_t i;
+  for (i = 0; i < *iovec_entries; ++i)
+    free(((*iovector)[i]).iov_base);
+  free(*iovector);
+  *iovector      = NULL;
+  *iovec_entries = 0;
+}
+
+void iovec_trim_last(size_t *iovec_entries, struct iovec **iovector, void *last_ptr) {
+  if (*iovec_entries) {
+    char  *base      = (char *)((*iovector)[*iovec_entries - 1]).iov_base;
+    size_t new_alloc = ((char *)last_ptr) - base;
+
+    ((*iovector)[*iovec_entries - 1]).iov_base = realloc(base, new_alloc);
+    ((*iovector)[*iovec_entries - 1]).iov_len  = new_alloc;
+  }
+}
+
+void *iovec_next_chunk(size_t *iovec_entries, struct iovec **iovector, void *last_ptr, size_t new_alloc) {
+  void *new_data;
+
+  iovec_trim_last(iovec_entries, iovector, last_ptr);
+
+  if (!(new_data = iovec_new_chunk(iovec_entries, iovector, new_alloc)))
+    iovec_free(iovec_entries, iovector);
+
+  return new_data;
+}
+
+size_t iovec_length(const size_t *iovec_entries, const struct iovec **iovector) {
+  size_t i, length = 0;
+  for (i = 0; i < *iovec_entries; ++i)
+    length += ((*iovector)[i]).iov_len;
+  return length;
+}