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libkmod: Improve index dump performance
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Use FILE for output to reduce the amount of system calls. Removes the
only use case of write_str_safe, which can be removed as well.

Signed-off-by: Tobias Stoeckmann <[email protected]>
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@stoeckmann
stoeckmann committed Nov 16, 2024
1 parent ebd0476 commit 2258f0d
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Showing 5 changed files with 45 additions and 51 deletions.
32 changes: 16 additions & 16 deletions libkmod/libkmod-index.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -360,7 +360,7 @@ static struct index_node_f *index_readchild(const struct index_node_f *parent, i
return NULL;
}

static void index_dump_node(struct index_node_f *node, struct strbuf *buf, int fd)
static void index_dump_node(struct index_node_f *node, struct strbuf *buf, FILE *fp)
{
struct index_value *v;
size_t pushed;
Expand All @@ -369,10 +369,10 @@ static void index_dump_node(struct index_node_f *node, struct strbuf *buf, int f
pushed = strbuf_pushchars(buf, node->prefix);

for (v = node->values; v != NULL; v = v->next) {
write_str_safe(fd, buf->bytes, buf->used);
write_str_safe(fd, " ", 1);
write_str_safe(fd, v->value, strlen(v->value));
write_str_safe(fd, "\n", 1);
fwrite(buf->bytes, 1, buf->used, fp);
fputc(' ', fp);
fputs(v->value, fp);
fputc('\n', fp);
}

for (ch = node->first; ch <= node->last; ch++) {
Expand All @@ -382,7 +382,7 @@ static void index_dump_node(struct index_node_f *node, struct strbuf *buf, int f
continue;

if (strbuf_pushchar(buf, ch)) {
index_dump_node(child, buf, fd);
index_dump_node(child, buf, fp);
strbuf_popchar(buf);
}
}
Expand All @@ -391,7 +391,7 @@ static void index_dump_node(struct index_node_f *node, struct strbuf *buf, int f
index_close(node);
}

void index_dump(struct index_file *in, int fd, bool alias_prefix)
void index_dump(struct index_file *in, FILE *fp, bool alias_prefix)
{
struct index_node_f *root;
struct strbuf buf;
Expand All @@ -402,7 +402,7 @@ void index_dump(struct index_file *in, int fd, bool alias_prefix)

strbuf_init(&buf);
if (!alias_prefix || strbuf_pushchars(&buf, "alias "))
index_dump_node(root, &buf, fd);
index_dump_node(root, &buf, fp);
strbuf_release(&buf);
}

Expand Down Expand Up @@ -821,7 +821,7 @@ static struct index_mm_node *index_mm_readchild(const struct index_mm_node *pare
return NULL;
}

static void index_mm_dump_node(struct index_mm_node *node, struct strbuf *buf, int fd)
static void index_mm_dump_node(struct index_mm_node *node, struct strbuf *buf, FILE *fp)
{
const void *p;
size_t i, pushed;
Expand All @@ -833,10 +833,10 @@ static void index_mm_dump_node(struct index_mm_node *node, struct strbuf *buf, i
struct index_mm_value v;

read_value_mm(&p, &v);
write_str_safe(fd, buf->bytes, buf->used);
write_str_safe(fd, " ", 1);
write_str_safe(fd, v.value, v.len);
write_str_safe(fd, "\n", 1);
fwrite(buf->bytes, 1, buf->used, fp);
fputc(' ', fp);
fwrite(v.value, 1, v.len, fp);
fputc('\n', fp);
}

for (ch = node->first; ch <= node->last; ch++) {
Expand All @@ -847,15 +847,15 @@ static void index_mm_dump_node(struct index_mm_node *node, struct strbuf *buf, i
continue;

if (strbuf_pushchar(buf, ch)) {
index_mm_dump_node(child, buf, fd);
index_mm_dump_node(child, buf, fp);
strbuf_popchar(buf);
}
}

strbuf_popchars(buf, pushed);
}

void index_mm_dump(const struct index_mm *idx, int fd, bool alias_prefix)
void index_mm_dump(const struct index_mm *idx, FILE *fp, bool alias_prefix)
{
struct index_mm_node nbuf, *root;
struct strbuf buf;
Expand All @@ -866,7 +866,7 @@ void index_mm_dump(const struct index_mm *idx, int fd, bool alias_prefix)

strbuf_init(&buf);
if (!alias_prefix || strbuf_pushchars(&buf, "alias "))
index_mm_dump_node(root, &buf, fd);
index_mm_dump_node(root, &buf, fp);
strbuf_release(&buf);
}

Expand Down
4 changes: 2 additions & 2 deletions libkmod/libkmod-index.h
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Original file line number Diff line number Diff line change
Expand Up @@ -19,7 +19,7 @@ struct index_file;
struct index_file *index_file_open(const char *filename);
void index_file_close(struct index_file *idx);
char *index_search(struct index_file *idx, const char *key);
void index_dump(struct index_file *in, int fd, bool alias_prefix);
void index_dump(struct index_file *in, FILE *fp, bool alias_prefix);
struct index_value *index_searchwild(struct index_file *idx, const char *key);

void index_values_free(struct index_value *values);
Expand All @@ -31,4 +31,4 @@ int index_mm_open(const struct kmod_ctx *ctx, const char *filename,
void index_mm_close(struct index_mm *index);
char *index_mm_search(const struct index_mm *idx, const char *key);
struct index_value *index_mm_searchwild(const struct index_mm *idx, const char *key);
void index_mm_dump(const struct index_mm *idx, int fd, bool alias_prefix);
void index_mm_dump(const struct index_mm *idx, FILE *fp, bool alias_prefix);
33 changes: 27 additions & 6 deletions libkmod/libkmod.c
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Original file line number Diff line number Diff line change
Expand Up @@ -810,22 +810,37 @@ KMOD_EXPORT void kmod_unload_resources(struct kmod_ctx *ctx)

KMOD_EXPORT int kmod_dump_index(struct kmod_ctx *ctx, enum kmod_index type, int fd)
{
int err, fd2;
FILE *fp;

if (ctx == NULL)
return -ENOSYS;

fd2 = dup(fd);
if (fd2 == -1)
return -errno;
fp = fdopen(fd2, "a");
if (fp == NULL) {
err = -errno;
close(fd2);
return err;
}

#if defined(__clang__)
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wtautological-unsigned-enum-zero-compare"
#endif
if (type < 0 || type >= _KMOD_INDEX_MODULES_SIZE)
return -ENOENT;
if (type < 0 || type >= _KMOD_INDEX_MODULES_SIZE) {
err = -ENOENT;
goto err;
}
#if defined(__clang__)
#pragma clang diagnostic pop
#endif

if (ctx->indexes[type] != NULL) {
DBG(ctx, "use mmapped index '%s'\n", index_files[type].fn);
index_mm_dump(ctx->indexes[type], fd, index_files[type].alias_prefix);
index_mm_dump(ctx->indexes[type], fp, index_files[type].alias_prefix);
} else {
char fn[PATH_MAX];
struct index_file *idx;
Expand All @@ -835,14 +850,20 @@ KMOD_EXPORT int kmod_dump_index(struct kmod_ctx *ctx, enum kmod_index type, int
DBG(ctx, "file=%s\n", fn);

idx = index_file_open(fn);
if (idx == NULL)
return -ENOSYS;
if (idx == NULL) {
err = -ENOSYS;
goto err;
}

index_dump(idx, fd, index_files[type].alias_prefix);
index_dump(idx, fp, index_files[type].alias_prefix);
index_file_close(idx);
}

fclose(fp);
return 0;
err:
fclose(fp);
return err;
}

const struct kmod_config *kmod_get_config(const struct kmod_ctx *ctx)
Expand Down
26 changes: 0 additions & 26 deletions shared/util.c
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Original file line number Diff line number Diff line change
Expand Up @@ -237,32 +237,6 @@ ssize_t read_str_safe(int fd, char *buf, size_t buflen)
return done;
}

ssize_t write_str_safe(int fd, const char *buf, size_t buflen)
{
size_t todo = buflen;
size_t done = 0;

assert_cc(EAGAIN == EWOULDBLOCK);

do {
ssize_t r = write(fd, buf + done, todo);

if (r == 0)
break;
else if (r > 0) {
todo -= r;
done += r;
} else {
if (errno == EAGAIN || errno == EINTR)
continue;
else
return -errno;
}
} while (todo > 0);

return done;
}

int read_str_long(int fd, long *value, int base)
{
char buf[32], *end;
Expand Down
1 change: 0 additions & 1 deletion shared/util.h
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Original file line number Diff line number Diff line change
Expand Up @@ -37,7 +37,6 @@ _nonnull_all_ bool path_ends_with_kmod_ext(const char *path, size_t len);
_must_check_ _nonnull_(2) ssize_t pread_str_safe(int fd, char *buf, size_t buflen,
off_t off);
_must_check_ _nonnull_(2) ssize_t read_str_safe(int fd, char *buf, size_t buflen);
_nonnull_(2) ssize_t write_str_safe(int fd, const char *buf, size_t buflen);
_must_check_ _nonnull_(2) int read_str_long(int fd, long *value, int base);
_must_check_ _nonnull_(2) int read_str_ulong(int fd, unsigned long *value, int base);
_nonnull_(1) char *freadline_wrapped(FILE *fp, unsigned int *linenum);
Expand Down

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