diff options
Diffstat (limited to 'xlators/features/changelog/lib/src/gf-changelog-helpers.c')
| -rw-r--r-- | xlators/features/changelog/lib/src/gf-changelog-helpers.c | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/xlators/features/changelog/lib/src/gf-changelog-helpers.c b/xlators/features/changelog/lib/src/gf-changelog-helpers.c new file mode 100644 index 00000000000..1eef8bf0479 --- /dev/null +++ b/xlators/features/changelog/lib/src/gf-changelog-helpers.c @@ -0,0 +1,180 @@ +/* + Copyright (c) 2013 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. +*/ + +#include "changelog-mem-types.h" +#include "gf-changelog-helpers.h" + +ssize_t gf_changelog_read_path (int fd, char *buffer, size_t bufsize) +{ + return read (fd, buffer, bufsize); +} + +size_t +gf_changelog_write (int fd, char *buffer, size_t len) +{ + ssize_t size = 0; + size_t writen = 0; + + while (writen < len) { + size = write (fd, + buffer + writen, len - writen); + if (size <= 0) + break; + + writen += size; + } + + return writen; +} + +void +gf_rfc3986_encode (unsigned char *s, char *enc, char *estr) +{ + for (; *s; s++) { + if (estr[*s]) + sprintf(enc, "%c", estr[*s]); + else + sprintf(enc, "%%%02X", *s); + while (*++enc); + } +} + +/** + * thread safe version of readline with buffering + * (taken from Unix Network Programming Volume I, W.R. Stevens) + * + * This is favoured over fgets() as we'd need to ftruncate() + * (see gf_changelog_scan() API) to record new changelog files. + * stream open functions does have a truncate like api (although + * that can be done via @fflush(fp), @ftruncate(fd) and @fseek(fp), + * but this involves mixing POSIX file descriptors and stream FILE *). + * + * NOTE: This implmentation still does work with more than one fd's + * used to perform gf_readline(). For this very reason it's not + * made a part of libglusterfs. + */ + +static pthread_key_t rl_key; +static pthread_once_t rl_once = PTHREAD_ONCE_INIT; + +static void +readline_destructor (void *ptr) +{ + GF_FREE (ptr); +} + +static void +readline_once (void) +{ + pthread_key_create (&rl_key, readline_destructor); +} + +static ssize_t +my_read (read_line_t *tsd, int fd, char *ptr) +{ + if (tsd->rl_cnt <= 0) { + if ( (tsd->rl_cnt = read (fd, tsd->rl_buf, MAXLINE)) < 0 ) + return -1; + else if (tsd->rl_cnt == 0) + return 0; + tsd->rl_bufptr = tsd->rl_buf; + } + + tsd->rl_cnt--; + *ptr = *tsd->rl_bufptr++; + return 1; +} + +static int +gf_readline_init_once (read_line_t **tsd) +{ + if (pthread_once (&rl_once, readline_once) != 0) + return -1; + + *tsd = pthread_getspecific (rl_key); + if (*tsd) + goto out; + + *tsd = GF_CALLOC (1, sizeof (**tsd), + gf_changelog_mt_libgfchangelog_rl_t); + if (!*tsd) + return -1; + + if (pthread_setspecific (rl_key, *tsd) != 0) + return -1; + + out: + return 0; +} + +ssize_t +gf_readline (int fd, void *vptr, size_t maxlen) +{ + size_t n = 0; + size_t rc = 0; + char c = ' '; + char *ptr = NULL; + read_line_t *tsd = NULL; + + if (gf_readline_init_once (&tsd)) + return -1; + + ptr = vptr; + for (n = 1; n < maxlen; n++) { + if ( (rc = my_read (tsd, fd, &c)) == 1 ) { + *ptr++ = c; + if (c == '\n') + break; + } else if (rc == 0) { + *ptr = '\0'; + return (n - 1); + } else + return -1; + } + + *ptr = '\0'; + return n; + +} + +off_t +gf_lseek (int fd, off_t offset, int whence) +{ + off_t off = 0; + read_line_t *tsd = NULL; + + if (gf_readline_init_once (&tsd)) + return -1; + + if ( (off = lseek (fd, offset, whence)) == -1) + return -1; + + tsd->rl_cnt = 0; + tsd->rl_bufptr = tsd->rl_buf; + + return off; +} + +int +gf_ftruncate (int fd, off_t length) +{ + read_line_t *tsd = NULL; + + if (gf_readline_init_once (&tsd)) + return -1; + + if (ftruncate (fd, 0)) + return -1; + + tsd->rl_cnt = 0; + tsd->rl_bufptr = tsd->rl_buf; + + return 0; +} |