1 files changed, 121 insertions, 0 deletions
diff --git a/libglusterfs/src/rot-buffs.h b/libglusterfs/src/rot-buffs.h
new file mode 100644
index 00000000000..aac24a4f571
--- /dev/null
+++ b/libglusterfs/src/rot-buffs.h
@@ -0,0 +1,121 @@
+/*
+  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 "list.h"
+#include "locking.h"
+#include "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 assigment 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