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diff --git a/cache.c b/cache.c
index e70af13..9c36f1a 100644
--- a/cache.c
+++ b/cache.c
@@ -97,6 +97,7 @@ static int print_slot(struct cache_slot *slot)
do {
ssize_t ret;
+ html_flush();
ret = sendfile(STDOUT_FILENO, slot->cache_fd, &off, size - off);
if (ret < 0) {
if (errno == EAGAIN || errno == EINTR)
@@ -121,6 +122,7 @@ static int print_slot(struct cache_slot *slot)
return errno;
if (ret == 0)
return 0;
+ html_flush();
if (write_in_full(STDOUT_FILENO, slot->buf, ret) < 0)
return errno;
} while (1);
@@ -207,6 +209,7 @@ static int unlock_slot(struct cache_slot *slot, int replace_old_slot)
/* Restore stdout and close the temporary FD. */
if (slot->stdout_fd >= 0) {
+ html_flush();
dup2(slot->stdout_fd, STDOUT_FILENO);
close(slot->stdout_fd);
slot->stdout_fd = -1;
@@ -224,6 +227,7 @@ static int unlock_slot(struct cache_slot *slot, int replace_old_slot)
static int fill_slot(struct cache_slot *slot)
{
/* Preserve stdout */
+ html_flush();
slot->stdout_fd = dup(STDOUT_FILENO);
if (slot->stdout_fd == -1)
return errno;
@@ -235,7 +239,10 @@ static int fill_slot(struct cache_slot *slot)
/* Generate cache content */
slot->fn();
- /* Make sure any buffered data is flushed to the file */
+ /* Make sure any buffered data is flushed to the file. This must
+ * happen before the fstat() below, which records the size used to
+ * serve the slot. */
+ html_flush();
if (fflush(stdout))
return errno;
diff --git a/cgit.c b/cgit.c
index a6ed39f..65e369c 100644
--- a/cgit.c
+++ b/cgit.c
@@ -686,6 +686,7 @@ static inline void authenticate_post(void)
len = MAX_AUTHENTICATION_POST_BYTES;
if ((len = read(STDIN_FILENO, buffer, len)) < 0)
die_errno("Could not read POST from stdin");
+ html_flush();
if (write(STDOUT_FILENO, buffer, len) < 0)
die_errno("Could not write POST to stdout");
cgit_close_filter(ctx.cfg.auth_filter);
@@ -1078,6 +1079,7 @@ int cmd_main(int argc, const char **argv)
int err, ttl;
cgit_init_filters();
+ atexit(html_flush);
atexit(cgit_cleanup_filters);
set_die_routine(cgit_die_routine);
diff --git a/filter.c b/filter.c
index c778d05..6b70cc2 100644
--- a/filter.c
+++ b/filter.c
@@ -48,6 +48,7 @@ static int open_exec_filter(struct cgit_filter *base, va_list ap)
for (i = 0; i < filter->base.argument_count; i++)
filter->argv[i + 1] = va_arg(ap, char *);
+ html_flush();
filter->old_stdout = chk_positive(dup(STDOUT_FILENO),
"Unable to duplicate STDOUT");
chk_zero(pipe(pipe_fh), "Unable to create pipe to subprocess");
@@ -71,6 +72,7 @@ static int close_exec_filter(struct cgit_filter *base)
struct cgit_exec_filter *filter = (struct cgit_exec_filter *)base;
int i, exit_status = 0;
+ html_flush();
chk_non_negative(dup2(filter->old_stdout, STDOUT_FILENO),
"Unable to restore STDOUT");
close(filter->old_stdout);
diff --git a/html.c b/html.c
index 0bac34b..1db7a17 100644
--- a/html.c
+++ b/html.c
@@ -78,12 +78,46 @@ char *fmtalloc(const char *format, ...)
return strbuf_detach(&sb, NULL);
}
-void html_raw(const char *data, size_t size)
+/*
+ * Output is accumulated here and flushed in large chunks. cgit emits HTML
+ * in very small pieces (a 1.7MB diff is ~99k html() calls), and one write()
+ * per piece is almost all syscall overhead. Anything that redirects fd 1
+ * (the cache slot, exec filters) must call html_flush() first, and so must
+ * any path that exits.
+ */
+#define HTML_BUFSZ (64 * 1024)
+static char html_buf[HTML_BUFSZ];
+static size_t html_buflen;
+
+static void html_write(const char *data, size_t size)
{
- if (write(STDOUT_FILENO, data, size) != size)
+ if (write_in_full(STDOUT_FILENO, data, size) < 0)
die_errno("write error on html output");
}
+void html_flush(void)
+{
+ if (!html_buflen)
+ return;
+ /* Clear first: die_errno() unwinds through here again. */
+ size_t n = html_buflen;
+ html_buflen = 0;
+ html_write(html_buf, n);
+}
+
+void html_raw(const char *data, size_t size)
+{
+ if (size >= HTML_BUFSZ) {
+ html_flush();
+ html_write(data, size);
+ return;
+ }
+ if (html_buflen + size > HTML_BUFSZ)
+ html_flush();
+ memcpy(html_buf + html_buflen, data, size);
+ html_buflen += size;
+}
+
void html(const char *txt)
{
html_raw(txt, strlen(txt));
diff --git a/html.h b/html.h
index fa4de77..1d384d9 100644
--- a/html.h
+++ b/html.h
@@ -4,6 +4,7 @@
#include "cgit.h"
extern void html_raw(const char *txt, size_t size);
+extern void html_flush(void);
extern void html(const char *txt);
__attribute__((format (printf,1,2)))
diff --git a/ui-shared.c b/ui-shared.c
index e015590..cb306bc 100644
--- a/ui-shared.c
+++ b/ui-shared.c
@@ -769,6 +769,12 @@ void cgit_print_http_headers(void)
if (ctx.page.etag)
htmlf("ETag: \"%s\"\n", ctx.page.etag);
html("\n");
+ /*
+ * Flush here so the headers reach the client before the body,
+ * whoever writes it. Snapshots and clone data are produced by
+ * git writing straight to fd 1, bypassing html_raw().
+ */
+ html_flush();
if (ctx.env.request_method && !strcmp(ctx.env.request_method, "HEAD"))
exit(0);
}
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