[lttng-dev] [PATCH 2/2] Implement bt_getline
Mathieu Desnoyers
mathieu.desnoyers at efficios.com
Tue Oct 13 14:44:06 EDT 2015
Implement our own getline to remove dependency from glibc 2.10+ and to
increase portability to other operating systems.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers at efficios.com>
---
converter/babeltrace-log.c | 5 +-
include/babeltrace/compat/stdio.h | 124 ++++++++++++++++++++++++++++++++++++++
tests/lib/test_ctf_writer.c | 7 ++-
3 files changed, 130 insertions(+), 6 deletions(-)
create mode 100644 include/babeltrace/compat/stdio.h
diff --git a/converter/babeltrace-log.c b/converter/babeltrace-log.c
index 5900b32..acbd0ee 100644
--- a/converter/babeltrace-log.c
+++ b/converter/babeltrace-log.c
@@ -24,8 +24,6 @@
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
- *
- * Depends on glibc 2.10 for getline().
*/
#define _GNU_SOURCE
@@ -47,6 +45,7 @@
#include <babeltrace/ctf/types.h>
#include <babeltrace/compat/uuid.h>
#include <babeltrace/compat/utc.h>
+#include <babeltrace/compat/stdio.h>
#include <babeltrace/endian.h>
#define NSEC_PER_USEC 1000UL
@@ -331,7 +330,7 @@ void trace_text(FILE *input, int output)
write_packet_header(&pos, s_uuid);
write_packet_context(&pos);
for (;;) {
- len = getline(&line, &linesize, input);
+ len = bt_getline(&line, &linesize, input);
if (len < 0)
break;
nl = strrchr(line, '\n');
diff --git a/include/babeltrace/compat/stdio.h b/include/babeltrace/compat/stdio.h
new file mode 100644
index 0000000..0301e28
--- /dev/null
+++ b/include/babeltrace/compat/stdio.h
@@ -0,0 +1,124 @@
+#ifndef _BABELTRACE_COMPAT_STDIO_H
+#define _BABELTRACE_COMPAT_STDIO_H
+
+/*
+ * Copyright (C) 2015 Mathieu Desnoyers <mathieu.desnoyers at efficios.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include <stdio.h>
+#include <errno.h>
+#include <assert.h>
+
+#define BT_GETLINE_MINBUFLEN 64
+
+static inline
+char * _bt_getline_bufalloc(char **lineptr, size_t *n, size_t linelen)
+{
+ size_t buflen = *n;
+ char *buf = *lineptr;
+
+ if (buflen >= linelen && buf != NULL) {
+ return buf;
+ }
+ if (buf == NULL) {
+ buflen = BT_GETLINE_MINBUFLEN;
+ } else {
+ buflen = buflen << 1;
+ if (buflen < BT_GETLINE_MINBUFLEN) {
+ buflen = BT_GETLINE_MINBUFLEN;
+ }
+ }
+ /* Check below not strictly needed, extra safety. */
+ if (buflen < linelen) {
+ buflen = linelen;
+ }
+ buf = realloc(buf, buflen);
+ if (!buf) {
+ errno = ENOMEM;
+ return NULL;
+ }
+ *n = buflen;
+ *lineptr = buf;
+ return buf;
+}
+
+/*
+ * Returns line length (including possible final \n, excluding final
+ * \0). On end of file, returns -1 with nonzero feof(stream) and errno
+ * set to 0. On error, returns -1 with errno set.
+ *
+ * This interface is similar to the getline(3) man page part of the
+ * Linux man-pages project, release 3.74. One major difference from the
+ * Open Group POSIX specification is that this implementation does not
+ * necessarily set the ferror() flag on error (because it is internal to
+ * libc).
+ */
+static inline
+ssize_t bt_getline(char **lineptr, size_t *n, FILE *stream)
+{
+ size_t linelen = 0;
+ char *buf;
+ int found_eof = 0;
+
+ if (lineptr == NULL || n == NULL) {
+ errno = EINVAL;
+ return -1;
+ }
+ for (;;) {
+ char c;
+
+ c = fgetc(stream);
+ if (c == EOF) {
+ if (ferror(stream)) {
+ /* ferror() is set, errno set by fgetc(). */
+ return -1;
+ }
+ assert(feof(stream));
+ found_eof = 1;
+ break;
+ }
+ if (linelen == SSIZE_MAX) {
+ errno = EOVERFLOW;
+ return -1;
+ }
+ buf = _bt_getline_bufalloc(lineptr, n, ++linelen);
+ if (!buf) {
+ return -1;
+ }
+ buf[linelen - 1] = c;
+ if (c == '\n') {
+ break;
+ }
+ }
+ if (!linelen && found_eof) {
+ /* feof() is set. */
+ errno = 0;
+ return -1;
+ }
+ buf = _bt_getline_bufalloc(lineptr, n, ++linelen);
+ if (!buf) {
+ return -1;
+ }
+ buf[linelen - 1] = '\0';
+ return linelen - 1; /* Count don't include final \0. */
+}
+
+#endif /* _BABELTRACE_COMPAT_STDIO_H */
diff --git a/tests/lib/test_ctf_writer.c b/tests/lib/test_ctf_writer.c
index b626a66..91ef81a 100644
--- a/tests/lib/test_ctf_writer.c
+++ b/tests/lib/test_ctf_writer.c
@@ -35,6 +35,7 @@
#include <stdio.h>
#include <sys/utsname.h>
#include <babeltrace/compat/limits.h>
+#include <babeltrace/compat/stdio.h>
#include <string.h>
#include <assert.h>
#include <sys/wait.h>
@@ -160,12 +161,12 @@ result:
rewind(metadata_fp);
/* Output the metadata and parser output as diagnostic */
- while (getline(&line, &len, metadata_fp) > 0) {
+ while (bt_getline(&line, &len, metadata_fp) > 0) {
fprintf(stderr, "# %s", line);
}
rewind(parser_output_fp);
- while (getline(&line, &len, parser_output_fp) > 0) {
+ while (bt_getline(&line, &len, parser_output_fp) > 0) {
fprintf(stderr, "# %s", line);
}
@@ -257,7 +258,7 @@ result:
diag("malloc error");
}
rewind(babeltrace_output_fp);
- while (getline(&line, &len, babeltrace_output_fp) > 0) {
+ while (bt_getline(&line, &len, babeltrace_output_fp) > 0) {
diag("%s", line);
}
--
2.1.4
More information about the lttng-dev
mailing list