1 files changed, 125 insertions, 0 deletions
diff --git a/libglusterfs/src/glusterfs/rot-buffs.h b/libglusterfs/src/glusterfs/rot-buffs.h
new file mode 100644
index 00000000000..9dc227d58b8
--- /dev/null
+++ b/libglusterfs/src/glusterfs/rot-buffs.h
@@ -0,0 +1,125 @@
+/*
+  Copyright (c) 2008-2015 Red Hat, Inc. <http://www.redhat.com>
+  This file is part of GlusterFS.
+
+  This file is licensed to you under your choice of the GNU Lesser
+  General Public License, version 3 or any later version (LGPLv3 or
+  later), or the GNU General Public License, version 2 (GPLv2), in all
+  cases as published by the Free Software Foundation.
+*/
+
+#ifndef __ROT_BUFFS_H
+#define __ROT_BUFFS_H
+
+#include "glusterfs/list.h"
+#include "glusterfs/locking.h"
+#include "glusterfs/common-utils.h"
+
+typedef struct rbuf_iovec {
+    struct iovec iov;
+
+    struct list_head list;
+} rbuf_iovec_t;
+
+#define RBUF_IOVEC_SIZE (sizeof(rbuf_iovec_t))
+
+typedef struct rbuf_list {
+    gf_lock_t c_lock;
+
+    pthread_mutex_t b_lock; /* protects this structure */
+    pthread_cond_t b_cond;  /* signal for writer completion */
+
+    gf_boolean_t awaiting;
+
+    unsigned long long pending;   /* pending writers */
+    unsigned long long completed; /* completed writers */
+
+    rbuf_iovec_t *rvec; /* currently used IO vector */
+
+    struct list_head veclist; /* list of attached rbuf_iov */
+
+    unsigned long long used;  /* consumable entries
+                                  attached in ->veclist */
+    unsigned long long total; /* total entries in ->veclist (used
+                                 during deallocation) */
+
+    unsigned long seq[2]; /* if interested, this whould store
+                             the start sequence number and the
+                             range */
+
+    struct list_head list; /* attachment to rbuf_t */
+} rbuf_list_t;
+
+struct rlist_iter {
+    struct list_head veclist;
+
+    unsigned long long iter;
+};
+
+#define RLIST_ENTRY_COUNT(rlist) rlist->used
+
+#define rlist_iter_init(riter, rlist)                                          \
+    do {                                                                       \
+        (riter)->iter = rlist->used;                                           \
+        (riter)->veclist = rlist->veclist;                                     \
+    } while (0)
+
+#define rvec_for_each_entry(pos, riter)                                        \
+    for (pos = list_entry((riter)->veclist.next, typeof(*pos), list);          \
+         (riter)->iter > 0;                                                    \
+         pos = list_entry(pos->list.next, typeof(*pos), list),                 \
+        --((riter)->iter))
+
+/**
+ * Sequence number assignment routine is called during buffer
+ * switch under rbuff ->lock.
+ */
+typedef void(sequence_fn)(rbuf_list_t *, void *);
+
+#define RLIST_STORE_SEQ(rlist, start, range)                                   \
+    do {                                                                       \
+        rlist->seq[0] = start;                                                 \
+        rlist->seq[1] = range;                                                 \
+    } while (0)
+
+#define RLIST_GET_SEQ(rlist, start, range)                                     \
+    do {                                                                       \
+        start = rlist->seq[0];                                                 \
+        range = rlist->seq[1];                                                 \
+    } while (0)
+
+typedef struct rbuf {
+    gf_lock_t lock; /* protects "current" rlist */
+
+    rbuf_list_t *current; /* cached pointer to first free rlist */
+
+    struct list_head freelist;
+} rbuf_t;
+
+typedef enum {
+    RBUF_CONSUMABLE = 1,
+    RBUF_BUSY,
+    RBUF_EMPTY,
+    RBUF_WOULD_STARVE,
+} rlist_retval_t;
+
+/* Initialization/Destruction */
+rbuf_t *
+rbuf_init(int);
+void
+rbuf_dtor(rbuf_t *);
+
+/* Producer API */
+char *
+rbuf_reserve_write_area(rbuf_t *, size_t, void **);
+int
+rbuf_write_complete(void *);
+
+/* Consumer API */
+int
+rbuf_get_buffer(rbuf_t *, void **, sequence_fn *, void *);
+int
+rbuf_wait_for_completion(rbuf_t *, void *, void (*)(rbuf_list_t *, void *),
+                         void *);
+
+#endif