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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /tools/perf/util/strbuf.c | |
parent | Initial commit. (diff) | |
download | linux-upstream.tar.xz linux-upstream.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'tools/perf/util/strbuf.c')
-rw-r--r-- | tools/perf/util/strbuf.c | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/tools/perf/util/strbuf.c b/tools/perf/util/strbuf.c new file mode 100644 index 000000000..a64a37628 --- /dev/null +++ b/tools/perf/util/strbuf.c @@ -0,0 +1,170 @@ +// SPDX-License-Identifier: GPL-2.0 +#include "cache.h" +#include "debug.h" +#include "strbuf.h" +#include <linux/kernel.h> +#include <linux/string.h> +#include <linux/zalloc.h> +#include <errno.h> +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> + +/* + * Used as the default ->buf value, so that people can always assume + * buf is non NULL and ->buf is NUL terminated even for a freshly + * initialized strbuf. + */ +char strbuf_slopbuf[1]; + +int strbuf_init(struct strbuf *sb, ssize_t hint) +{ + sb->alloc = sb->len = 0; + sb->buf = strbuf_slopbuf; + if (hint) + return strbuf_grow(sb, hint); + return 0; +} + +void strbuf_release(struct strbuf *sb) +{ + if (sb->alloc) { + zfree(&sb->buf); + strbuf_init(sb, 0); + } +} + +char *strbuf_detach(struct strbuf *sb, size_t *sz) +{ + char *res = sb->alloc ? sb->buf : NULL; + if (sz) + *sz = sb->len; + strbuf_init(sb, 0); + return res; +} + +int strbuf_grow(struct strbuf *sb, size_t extra) +{ + char *buf; + size_t nr = sb->len + extra + 1; + + if (nr < sb->alloc) + return 0; + + if (nr <= sb->len) + return -E2BIG; + + if (alloc_nr(sb->alloc) > nr) + nr = alloc_nr(sb->alloc); + + /* + * Note that sb->buf == strbuf_slopbuf if sb->alloc == 0, and it is + * a static variable. Thus we have to avoid passing it to realloc. + */ + buf = realloc(sb->alloc ? sb->buf : NULL, nr * sizeof(*buf)); + if (!buf) + return -ENOMEM; + + sb->buf = buf; + sb->alloc = nr; + return 0; +} + +int strbuf_addch(struct strbuf *sb, int c) +{ + int ret = strbuf_grow(sb, 1); + if (ret) + return ret; + + sb->buf[sb->len++] = c; + sb->buf[sb->len] = '\0'; + return 0; +} + +int strbuf_add(struct strbuf *sb, const void *data, size_t len) +{ + int ret = strbuf_grow(sb, len); + if (ret) + return ret; + + memcpy(sb->buf + sb->len, data, len); + return strbuf_setlen(sb, sb->len + len); +} + +static int strbuf_addv(struct strbuf *sb, const char *fmt, va_list ap) +{ + int len, ret; + va_list ap_saved; + + if (!strbuf_avail(sb)) { + ret = strbuf_grow(sb, 64); + if (ret) + return ret; + } + + va_copy(ap_saved, ap); + len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap); + if (len < 0) { + va_end(ap_saved); + return len; + } + if (len > strbuf_avail(sb)) { + ret = strbuf_grow(sb, len); + if (ret) { + va_end(ap_saved); + return ret; + } + len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap_saved); + if (len > strbuf_avail(sb)) { + pr_debug("this should not happen, your vsnprintf is broken"); + va_end(ap_saved); + return -EINVAL; + } + } + va_end(ap_saved); + return strbuf_setlen(sb, sb->len + len); +} + +int strbuf_addf(struct strbuf *sb, const char *fmt, ...) +{ + va_list ap; + int ret; + + va_start(ap, fmt); + ret = strbuf_addv(sb, fmt, ap); + va_end(ap); + return ret; +} + +ssize_t strbuf_read(struct strbuf *sb, int fd, ssize_t hint) +{ + size_t oldlen = sb->len; + size_t oldalloc = sb->alloc; + int ret; + + ret = strbuf_grow(sb, hint ? hint : 8192); + if (ret) + return ret; + + for (;;) { + ssize_t cnt; + + cnt = read(fd, sb->buf + sb->len, sb->alloc - sb->len - 1); + if (cnt < 0) { + if (oldalloc == 0) + strbuf_release(sb); + else + strbuf_setlen(sb, oldlen); + return cnt; + } + if (!cnt) + break; + sb->len += cnt; + ret = strbuf_grow(sb, 8192); + if (ret) + return ret; + } + + sb->buf[sb->len] = '\0'; + return sb->len - oldlen; +} |