1 files changed, 46 insertions, 0 deletions

diff --git a/src/ot_batch.h b/src/ot_batch.h
new file mode 100644
index 0000000..910bea7
--- /dev/null
+++ b/src/ot_batch.h
@@ -0,0 +1,46 @@
+/* This software was written by Dirk Engling <erdgeist@erdgeist.org>
+   It is considered beerware. Prost. Skol. Cheers or whatever. */
+
+#ifndef OT_BATCH_H__
+#define OT_BATCH_H__
+
+#include <stddef.h>
+#include <sys/types.h>
+#include <sys/uio.h>
+
+/* A queue of buffers on their way to one socket. The batch owns every buffer
+   handed to it and frees each one as soon as it has left, so a client that
+   reads slowly costs memory only for what it has not received yet.
+
+   A zeroed ot_batch is ready to use. */
+typedef struct {
+  struct iovec *entries;
+  size_t        space;
+  size_t        count;
+  size_t        first;  /* entries before this one are sent and freed */
+  size_t        offset; /* bytes of entries[first] already sent */
+} ot_batch;
+
+static inline int batch_pending(const ot_batch *batch) { return batch->first != batch->count; }
+
+/* What batch_send reports instead of a byte count */
+enum { BATCH_DONE = 0, BATCH_AGAIN = -1, BATCH_FAILED = -2 };
+
+/* Queue buf and take ownership of it. Returns 0, or -1 having freed buf. */
+int     batch_add(ot_batch *batch, void *buf, size_t len);
+
+/* Write as much as the socket takes. Returns the number of bytes written, or
+   BATCH_DONE, BATCH_AGAIN or BATCH_FAILED. */
+ssize_t batch_send(int s, ot_batch *batch);
+
+/* Queue every entry of a vector, taking ownership of each buffer but not of
+   the vector itself. Returns 0, or -1 having freed all of them. */
+int     batch_add_vector(ot_batch *batch, const struct iovec *entries, size_t count);
+
+/* Queue a copy of buf, which the batch then owns. Returns 0, or -1. */
+int     batch_add_copy(ot_batch *batch, const void *buf, size_t len);
+
+/* Free whatever has not left yet, along with the batch's own array */
+void    batch_reset(ot_batch *batch);
+
+#endif