From a86ea83b5a20eb75bc86a66f6feeb7f3c1520719 Mon Sep 17 00:00:00 2001
From: Glenn Strauss <gstrauss@gluelogic.com>
Date: Sun, 12 May 2019 18:31:43 -0400
Subject: [PATCH] [core] chunkqueue perf: read small files into mem

---
 src/http-header-glue.c | 10 +++++++---
 src/http_chunk.c       | 39 +++++++++++++++++++++++++++++++++++++--
 src/http_chunk.h       |  2 +-
 3 files changed, 45 insertions(+), 6 deletions(-)

diff --git a/src/http-header-glue.c b/src/http-header-glue.c
index 08cc03cb..b7f03309 100644
--- a/src/http-header-glue.c
+++ b/src/http-header-glue.c
@@ -591,9 +591,13 @@ void http_response_send_file (server *srv, connection *con, buffer *path) {
 	 * the HEAD request will drop it afterwards again
 	 */
 
-	http_chunk_append_file_fd(srv, con, path, fd, sce->st.st_size);
-	con->http_status = 200;
-	con->file_finished = 1;
+	if (0 == http_chunk_append_file_fd(srv, con, path, fd, sce->st.st_size)) {
+		con->http_status = 200;
+		con->file_finished = 1;
+	}
+	else {
+		con->http_status = 500;
+	}
 }
 
 
diff --git a/src/http_chunk.c b/src/http_chunk.c
index 302e94b3..e973d6e0 100644
--- a/src/http_chunk.c
+++ b/src/http_chunk.c
@@ -43,6 +43,36 @@ static int http_chunk_append_file_open_fstat(server *srv, connection *con, buffe
 	return stat_cache_open_rdonly_fstat(fn, st, con->conf.follow_symlink);
 }
 
+static int http_chunk_append_read_fd_range(server *srv, connection *con, buffer *fn, int fd, off_t offset, off_t len) {
+    /* note: this routine should not be used for range requests
+     * unless the total size of ranges requested is small */
+    /* note: future: could read into existing MEM_CHUNK in cq->last if
+     * there is sufficient space, but would need to adjust for existing
+     * offset in for cq->bytes_in in chunkqueue_append_buffer_commit() */
+    UNUSED(fn);
+
+    if (con->response.send_chunked) {
+        http_chunk_append_len(srv, con, (uintmax_t)len);
+    }
+
+    if (0 != offset && -1 == lseek(fd, offset, SEEK_SET)) return -1;
+    chunkqueue * const cq = con->write_queue;
+    buffer * const b = chunkqueue_append_buffer_open_sz(cq, len+2);
+    ssize_t rd;
+    offset = 0;
+    do {
+        rd = read(fd, b->ptr+offset, len-offset);
+    } while ((rd > 0 && (offset += rd, len -= rd)) || errno == EINTR);
+    buffer_commit(b, offset);
+
+    if (con->response.send_chunked) {
+        buffer_append_string_len(b, CONST_STR_LEN("\r\n"));
+    }
+
+    chunkqueue_append_buffer_commit(cq);
+    return (rd >= 0) ? 0 : -1;
+}
+
 static void http_chunk_append_file_fd_range(server *srv, connection *con, buffer *fn, int fd, off_t offset, off_t len) {
 	chunkqueue *cq = con->write_queue;
 
@@ -85,11 +115,16 @@ int http_chunk_append_file(server *srv, connection *con, buffer *fn) {
 	return 0;
 }
 
-void http_chunk_append_file_fd(server *srv, connection *con, buffer *fn, int fd, off_t sz) {
-	if (0 != sz) {
+int http_chunk_append_file_fd(server *srv, connection *con, buffer *fn, int fd, off_t sz) {
+	if (sz > 32768) {
 		http_chunk_append_file_fd_range(srv, con, fn, fd, 0, sz);
+		return 0;
 	} else {
+		int rc = (0 != sz) /*(read small files into memory)*/
+		  ? http_chunk_append_read_fd_range(srv, con, fn, fd, 0, sz)
+		  : 0;
 		close(fd);
+		return rc;
 	}
 }
 
diff --git a/src/http_chunk.h b/src/http_chunk.h
index 404c3a10..d426a997 100644
--- a/src/http_chunk.h
+++ b/src/http_chunk.h
@@ -8,7 +8,7 @@ int http_chunk_append_mem(server *srv, connection *con, const char * mem, size_t
 int http_chunk_append_buffer(server *srv, connection *con, buffer *mem); /* may reset "mem" */
 int http_chunk_transfer_cqlen(server *srv, connection *con, chunkqueue *src, size_t len);
 int http_chunk_append_file(server *srv, connection *con, buffer *fn); /* copies "fn" */
-void http_chunk_append_file_fd(server *srv, connection *con, buffer *fn, int fd, off_t sz);
+int http_chunk_append_file_fd(server *srv, connection *con, buffer *fn, int fd, off_t sz);
 int http_chunk_append_file_range(server *srv, connection *con, buffer *fn, off_t offset, off_t len); /* copies "fn" */
 void http_chunk_close(server *srv, connection *con);
 
-- 
2.11.4.GIT