ibuf: rename ibuf_*() to memcached_ibuf_*()

See [1] for the problem root and [2] for analysis. In brief: `ibuf_*()`
symbols may clash with the same named symbols in tarantool, so it worth
to rename them to avoid effects of different binary layouts: assertion
fails and memory corruptions.

For example, `ibuf_reserve_slow()` calls `slab_get()` and `slab_put()`.
If something will be changed in tarantool's slab cache, we can meet
problems in the module.

This patch just renames the `ibuf_*()` functions. It is the most simple
and durable workaround of the problem.

It is likely not necessary to rename inline functions, but since I'm not
dead sure, I renamed them all.

It is the last known problem from #59. All others are confirmed as safe
to ignore if we'll keep current libsmall version in the module (see the
analysis in [2]).

[1]: tarantool/tarantool#6873
[2]: #59 (comment)

Fixes #59

Author: Totktonada

memcached/internal/memcached.c

@@ -49,9 +49,9 @@
 static inline int
 memcached_skip_request(struct memcached_connection *con) {
 	struct ibuf *in = con->in;
-	while (ibuf_used(in) < con->len && con->noprocess) {
-		con->len -= ibuf_used(in);
-		ibuf_reset(in);
+	while (memcached_ibuf_used(in) < con->len && con->noprocess) {
+		con->len -= memcached_ibuf_used(in);
+		memcached_ibuf_reset(in);
 		ssize_t read = mnet_read_ibuf(con->fd, in, 1);
 		if (read == -1)
 			memcached_error_ENOMEM(1, "ibuf");
@@ -70,10 +70,10 @@ memcached_flush(struct memcached_connection *con) {
 				    obuf_iovcnt(con->out),
 				    obuf_size(con->out));
 	con->cfg->stat.bytes_written += total;
-	if (ibuf_used(con->in) == 0)
-		ibuf_reset(con->in);
+	if (memcached_ibuf_used(con->in) == 0)
+		memcached_ibuf_reset(con->in);
 	obuf_reset(con->out);
-	if (ibuf_reserve(con->in, con->cfg->readahead) == NULL)
+	if (memcached_ibuf_reserve(con->in, con->cfg->readahead) == NULL)
 		return -1;
 	return total;
 }
@@ -92,7 +92,7 @@ memcached_connection_gc(struct memcached_connection *con)
 static inline int
 memcached_loop_read(struct memcached_connection *con, size_t to_read)
 {
-	if (ibuf_reserve(con->in, to_read) == NULL) {
+	if (memcached_ibuf_reserve(con->in, to_read) == NULL) {
 /*		memcached_error_ENOMEM(to_read, "ibuf");*/
 		return -1;
 	}
@@ -198,7 +198,7 @@ memcached_loop(struct memcached_connection *con)
 		if (con->close_connection) {
 			say_debug("Requesting exit. Exiting.");
 			break;
-		} else if (rc == 0 && ibuf_used(con->in) > 0 &&
+		} else if (rc == 0 && memcached_ibuf_used(con->in) > 0 &&
 			   batch_count < con->cfg->batch_count) {
 			batch_count++;
 			goto next;
@@ -208,7 +208,7 @@ memcached_loop(struct memcached_connection *con)
 			memcached_flush(con);
 		fiber_reschedule();
 		batch_count = 0;
-		if (ibuf_used(con->in) > 0) {
+		if (memcached_ibuf_used(con->in) > 0) {
 			goto next;
 		}
 		continue;

memcached/internal/network.c

@@ -48,7 +48,7 @@ ibuf_new()
 {
 	void *ibuf = mempool_alloc(&ibuf_pool);
 	if (ibuf == NULL) return NULL;
-	ibuf_create((struct ibuf *)ibuf, cord_slab_cache(), iobuf_readahead);
+	memcached_ibuf_create((struct ibuf *)ibuf, cord_slab_cache(), iobuf_readahead);
 	return ibuf;
 }
 
@@ -64,7 +64,7 @@ obuf_new()
 void
 iobuf_delete(struct ibuf *ibuf, struct obuf *obuf)
 {
-	ibuf_destroy(ibuf);
+	memcached_ibuf_destroy(ibuf);
 	obuf_destroy(obuf);
 	mempool_free(&ibuf_pool, ibuf);
 	mempool_free(&obuf_pool, obuf);
@@ -147,10 +147,11 @@ mnet_read_ahead(int fd, void *buf, size_t bufsz, size_t sz)
 size_t
 mnet_read_ibuf(int fd, struct ibuf *buf, size_t sz)
 {
-	if (ibuf_reserve(buf, sz) == NULL) {
+	if (memcached_ibuf_reserve(buf, sz) == NULL) {
 		return -1;
 	}
-	ssize_t n = mnet_read_ahead(fd, buf->wpos, ibuf_unused(buf), sz);
+	ssize_t n = mnet_read_ahead(fd, buf->wpos, memcached_ibuf_unused(buf),
+				    sz);
 	buf->wpos += n;
 	return n;
 }

third_party/memcached_ibuf.c

@@ -34,7 +34,8 @@
 
 /** Initialize an input buffer. */
 void
-ibuf_create(struct ibuf *ibuf, struct slab_cache *slabc, size_t start_capacity)
+memcached_ibuf_create(struct ibuf *ibuf, struct slab_cache *slabc,
+		      size_t start_capacity)
 {
 	ibuf->slabc = slabc;
 	ibuf->buf = ibuf->rpos = ibuf->wpos = ibuf->end = NULL;
@@ -43,7 +44,7 @@ ibuf_create(struct ibuf *ibuf, struct slab_cache *slabc, size_t start_capacity)
 }
 
 void
-ibuf_destroy(struct ibuf *ibuf)
+memcached_ibuf_destroy(struct ibuf *ibuf)
 {
 	if (ibuf->buf) {
 		struct slab *slab = slab_from_data(ibuf->buf);
@@ -53,12 +54,12 @@ ibuf_destroy(struct ibuf *ibuf)
 
 /** Free memory allocated by this buffer */
 void
-ibuf_reinit(struct ibuf *ibuf)
+memcached_ibuf_reinit(struct ibuf *ibuf)
 {
 	struct slab_cache *slabc = ibuf->slabc;
 	size_t start_capacity = ibuf->start_capacity;
-	ibuf_destroy(ibuf);
-	ibuf_create(ibuf, slabc, start_capacity);
+	memcached_ibuf_destroy(ibuf);
+	memcached_ibuf_create(ibuf, slabc, start_capacity);
 }
 
 /**
@@ -67,11 +68,11 @@ ibuf_reinit(struct ibuf *ibuf)
  * the beginning.
  */
 void *
-ibuf_reserve_slow(struct ibuf *ibuf, size_t size)
+memcached_ibuf_reserve_slow(struct ibuf *ibuf, size_t size)
 {
 	assert(ibuf->wpos + size > ibuf->end);
-	size_t used = ibuf_used(ibuf);
-	size_t capacity = ibuf_capacity(ibuf);
+	size_t used = memcached_ibuf_used(ibuf);
+	size_t capacity = memcached_ibuf_capacity(ibuf);
 	/*
 	 * Check if we have enough space in the
 	 * current buffer. In this case de-fragment it

third_party/memcached_ibuf.h

@@ -1,5 +1,5 @@
-#ifndef TARANTOOL_SMALL_IBUF_H_INCLUDED
-#define TARANTOOL_SMALL_IBUF_H_INCLUDED
+#ifndef MEMCACHED_IBUF_H_INCLUDED
+#define MEMCACHED_IBUF_H_INCLUDED
 /*
  * Copyright 2010-2016, Tarantool AUTHORS, please see AUTHORS file.
  *
@@ -69,33 +69,34 @@ struct ibuf
 };
 
 void
-ibuf_create(struct ibuf *ibuf, struct slab_cache *slabc, size_t start_capacity);
+memcached_ibuf_create(struct ibuf *ibuf, struct slab_cache *slabc,
+		      size_t start_capacity);
 
 void
-ibuf_destroy(struct ibuf *ibuf);
+memcached_ibuf_destroy(struct ibuf *ibuf);
 
 void
-ibuf_reinit(struct ibuf *ibuf);
+memcached_ibuf_reinit(struct ibuf *ibuf);
 
 /** How much data is read and is not parsed yet. */
 static inline size_t
-ibuf_used(struct ibuf *ibuf)
+memcached_ibuf_used(struct ibuf *ibuf)
 {
 	assert(ibuf->wpos >= ibuf->rpos);
 	return ibuf->wpos - ibuf->rpos;
 }
 
 /** How much data can we fit beyond buf->wpos */
 static inline size_t
-ibuf_unused(struct ibuf *ibuf)
+memcached_ibuf_unused(struct ibuf *ibuf)
 {
 	assert(ibuf->wpos <= ibuf->end);
 	return ibuf->end - ibuf->wpos;
 }
 
 /** How much memory is allocated */
 static inline size_t
-ibuf_capacity(struct ibuf *ibuf)
+memcached_ibuf_capacity(struct ibuf *ibuf)
 {
 	return ibuf->end - ibuf->buf;
 }
@@ -105,38 +106,38 @@ ibuf_capacity(struct ibuf *ibuf)
  * in case of realloc.
  */
 static inline size_t
-ibuf_pos(struct ibuf *ibuf)
+memcached_ibuf_pos(struct ibuf *ibuf)
 {
 	assert(ibuf->buf <= ibuf->rpos);
 	return ibuf->rpos - ibuf->buf;
 }
 
 /** Forget all cached input. */
 static inline void
-ibuf_reset(struct ibuf *ibuf)
+memcached_ibuf_reset(struct ibuf *ibuf)
 {
 	ibuf->rpos = ibuf->wpos = ibuf->buf;
 }
 
 void *
-ibuf_reserve_slow(struct ibuf *ibuf, size_t size);
+memcached_ibuf_reserve_slow(struct ibuf *ibuf, size_t size);
 
 static inline void *
-ibuf_reserve(struct ibuf *ibuf, size_t size)
+memcached_ibuf_reserve(struct ibuf *ibuf, size_t size)
 {
 	if (ibuf->wpos + size <= ibuf->end)
 		return ibuf->wpos;
-	return ibuf_reserve_slow(ibuf, size);
+	return memcached_ibuf_reserve_slow(ibuf, size);
 }
 
 static inline void *
-ibuf_alloc(struct ibuf *ibuf, size_t size)
+memcached_ibuf_alloc(struct ibuf *ibuf, size_t size)
 {
 	void *ptr;
 	if (ibuf->wpos + size <= ibuf->end)
 		ptr = ibuf->wpos;
 	else {
-		ptr = ibuf_reserve_slow(ibuf, size);
+		ptr = memcached_ibuf_reserve_slow(ibuf, size);
 		if (ptr == NULL)
 			return NULL;
 	}
@@ -145,22 +146,23 @@ ibuf_alloc(struct ibuf *ibuf, size_t size)
 }
 
 static inline void *
-ibuf_reserve_cb(void *ctx, size_t *size)
+memcached_ibuf_reserve_cb(void *ctx, size_t *size)
 {
 	struct ibuf *buf = (struct ibuf *) ctx;
-	void *p = ibuf_reserve(buf, *size ? *size : buf->start_capacity);
-	*size = ibuf_unused(buf);
+	void *p = memcached_ibuf_reserve(
+		buf, *size ? *size : buf->start_capacity);
+	*size = memcached_ibuf_unused(buf);
 	return p;
 }
 
 static inline void *
-ibuf_alloc_cb(void *ctx, size_t size)
+memcached_ibuf_alloc_cb(void *ctx, size_t size)
 {
-	return ibuf_alloc((struct ibuf *) ctx, size);
+	return memcached_ibuf_alloc((struct ibuf *) ctx, size);
 }
 
 #if defined(__cplusplus)
 } /* extern "C" */
 #endif /* defined(__cplusplus) */
 
-#endif /* TARANTOOL_SMALL_IBUF_H_INCLUDED */
+#endif /* MEMCACHED_IBUF_H_INCLUDED */