From 2da51737c49f7917a974bdf9e6e566307583ad16 Mon Sep 17 00:00:00 2001 From: Anand Avati Date: Thu, 27 Mar 2014 21:21:12 -0700 Subject: strfd: memory backed file descriptor A file descriptor like interface, backed by a string, on which fprintf() like IO can be performed. Internally the backing string is grown on demand. Useful in generating virtual file content on the fly (used in meta) Change-Id: I60d8751c4c750f3f06aa454a4ccd9909b3ac8ac7 BUG: 1089216 Signed-off-by: Anand Avati Reviewed-on: http://review.gluster.org/7508 Reviewed-by: Pranith Kumar Karampuri Tested-by: Gluster Build System --- libglusterfs/src/Makefile.am | 4 +- libglusterfs/src/mem-types.h | 4 +- libglusterfs/src/strfd.c | 91 ++++++++++++++++++++++++++++++++++++++++++++ libglusterfs/src/strfd.h | 28 ++++++++++++++ 4 files changed, 124 insertions(+), 3 deletions(-) create mode 100644 libglusterfs/src/strfd.c create mode 100644 libglusterfs/src/strfd.h (limited to 'libglusterfs') diff --git a/libglusterfs/src/Makefile.am b/libglusterfs/src/Makefile.am index b1a853687..8934b35f2 100644 --- a/libglusterfs/src/Makefile.am +++ b/libglusterfs/src/Makefile.am @@ -26,7 +26,7 @@ libglusterfs_la_SOURCES = dict.c xlator.c logging.c \ graph-print.c trie.c run.c options.c fd-lk.c circ-buff.c \ event-history.c gidcache.c ctx.c client_t.c event-poll.c event-epoll.c \ $(CONTRIBDIR)/libgen/basename_r.c $(CONTRIBDIR)/libgen/dirname_r.c \ - $(CONTRIBDIR)/stdlib/gf_mkostemp.c + $(CONTRIBDIR)/stdlib/gf_mkostemp.c strfd.c nodist_libglusterfs_la_SOURCES = y.tab.c graph.lex.c gf-error-codes.h @@ -43,7 +43,7 @@ noinst_HEADERS = common-utils.h defaults.h dict.h glusterfs.h hashfn.h timespec. $(CONTRIB_BUILDDIR)/uuid/uuid_types.h syncop.h graph-utils.h trie.h \ run.h options.h lkowner.h fd-lk.h circ-buff.h event-history.h \ gidcache.h client_t.h glusterfs-acl.h glfs-message-id.h \ - template-component-messages.h + template-component-messages.h strfd.h EXTRA_DIST = graph.l graph.y diff --git a/libglusterfs/src/mem-types.h b/libglusterfs/src/mem-types.h index c01dfa75e..c07d1387b 100644 --- a/libglusterfs/src/mem-types.h +++ b/libglusterfs/src/mem-types.h @@ -122,6 +122,8 @@ enum gf_common_mem_types_ { gf_common_mt_uuid_t = 106, gf_common_mt_mgmt_v3_lock_obj_t = 107, gf_common_mt_txn_opinfo_obj_t = 108, - gf_common_mt_end = 109 + gf_common_mt_strfd_t = 109, + gf_common_mt_strfd_data_t = 110, + gf_common_mt_end }; #endif diff --git a/libglusterfs/src/strfd.c b/libglusterfs/src/strfd.c new file mode 100644 index 000000000..8c97670d4 --- /dev/null +++ b/libglusterfs/src/strfd.c @@ -0,0 +1,91 @@ +/* + Copyright (c) 2014 Red Hat, Inc. + 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 _CONFIG_H +#define _CONFIG_H +#include "config.h" +#endif + +#include + +#include "mem-types.h" +#include "mem-pool.h" +#include "strfd.h" +#include "common-utils.h" + + +strfd_t * +strfd_open () +{ + strfd_t *strfd = NULL; + + strfd = GF_CALLOC(1, sizeof(*strfd), gf_common_mt_strfd_t); + + return strfd; +} + + +int +strprintf (strfd_t *strfd, const char *fmt, ...) +{ + va_list ap; + char *str = NULL; + int size = 0; + + va_start (ap, fmt); + + size = vasprintf (&str, fmt, ap); + + if (size < 0) + return size; + + if (!strfd->alloc_size) { + strfd->data = GF_CALLOC (max(size + 1, 4096), 1, + gf_common_mt_strfd_data_t); + if (!strfd->data) { + free (str); /* NOT GF_FREE */ + return -1; + } + strfd->alloc_size = max(size + 1, 4096); + } + + if (strfd->alloc_size <= (strfd->size + size)) { + char *tmp_ptr = NULL; + int new_size = max ((strfd->alloc_size * 2), + gf_roundup_next_power_of_two (strfd->size + size + 1)); + tmp_ptr = GF_REALLOC (strfd->data, new_size); + if (!tmp_ptr) { + free (str); /* NOT GF_FREE */ + return -1; + } + strfd->alloc_size = new_size; + strfd->data = tmp_ptr; + } + + // Copy the trailing '\0', but do not account for it in ->size. + // This allows safe use of strfd->data as a string. + memcpy (strfd->data + strfd->size, str, size + 1); + strfd->size += size; + + free (str); /* NOT GF_FREE */ + + return size; +} + + +int +strfd_close (strfd_t *strfd) +{ + GF_FREE (strfd->data); + GF_FREE (strfd); + + return 0; +} + diff --git a/libglusterfs/src/strfd.h b/libglusterfs/src/strfd.h new file mode 100644 index 000000000..e386c8432 --- /dev/null +++ b/libglusterfs/src/strfd.h @@ -0,0 +1,28 @@ +/* + Copyright (c) 2014 Red Hat, Inc. + 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 _STRFD_H +#define _STRFD_H + +typedef struct { + void *data; + size_t alloc_size; + size_t size; + off_t pos; +} strfd_t; + +strfd_t *strfd_open(); + +int strprintf(strfd_t *strfd, const char *fmt, ...) + __attribute__ ((__format__ (__printf__, 2, 3))); + +int strfd_close(strfd_t *strfd); + +#endif -- cgit