Introduce MG_EV_HTTP_HDRS

examples/file-upload-single-post/main.c

@@ -2,51 +2,60 @@
 // All rights reserved
 //
 // Streaming upload example. Demonstrates how to use MG_EV_READ events
-// to get large payload in smaller chunks. To test, use curl utility:
+// to save a large file without buffering it fully in memory.
 //
 // curl http://localhost:8000/upload?name=a.txt --data-binary @large_file.txt
 
 #include "mongoose.h"
 
-// HTTP request handler function. It implements the following endpoints:
-//   /upload - Saves the next file chunk
-//   all other URI - serves web_root/ directory
-static void fn(struct mg_connection *c, int ev, void *ev_data) {
-  if (ev == MG_EV_READ) {
-    // Parse the incoming data ourselves. If we can parse the request,
-    // store two size_t variables in the c->data: expected len and recv len.
-    size_t *data = (size_t *) c->data;
-    if (data[0]) {  // Already parsed, simply print received data
-      data[1] += c->recv.len;
-      MG_INFO(("Got chunk len %lu, %lu total", c->recv.len, data[1]));
-      c->recv.len = 0;  // And cleanup the receive buffer. Streaming!
-      if (data[1] >= data[0]) mg_http_reply(c, 200, "", "ok\n");
-    } else {
-      struct mg_http_message hm;
-      int n = mg_http_parse((char *) c->recv.buf, c->recv.len, &hm);
-      if (n < 0) mg_error(c, "Bad response");
-      if (n > 0) {
-        if (mg_http_match_uri(&hm, "/upload")) {
-          MG_INFO(("Got chunk len %lu", c->recv.len - n));
-          data[0] = hm.body.len;
-          data[1] = c->recv.len - n;
-          if (data[1] >= data[0]) mg_http_reply(c, 200, "", "ok\n");
-        } else {
-          struct mg_http_serve_opts opts = {.root_dir = "web_root"};
-          mg_http_serve_dir(c, &hm, &opts);
-        }
-      }
+static void handle_uploads(struct mg_connection *c, int ev, void *ev_data) {
+  size_t *data = (size_t *) c->data;
+
+  // Catch /upload requests early, without buffering whole body:
+  if (ev == MG_EV_HTTP_HDRS) {
+    struct mg_http_message *hm = (struct mg_http_message *) ev_data;
+    if (mg_match(hm->uri, mg_str("/upload"), NULL)) {
+      // When we receive MG_EV_HTTP_HDRS event, that means we've received all
+      // HTTP headers but not necessarily full HTTP body. We save HTTP body
+      // length in data[0]:
+      // data[0] contains expected number of bytes
+      // data[1] contains received number of bytes
+      data[0] = hm->body.len;  // Store number of bytes we expect
+      mg_iobuf_del(&c->recv, 0, hm->head.len);  // Delete HTTP headers
+      c->pfn = NULL;  // Silence HTTP protocol handler, we'll use MG_EV_READ
+    }
+  }
+
+  // Catch uploaded file data for both MG_EV_READ and MG_EV_HTTP_HDRS
+  if (data[0] > 0 && c->recv.len > 0) {
+    data[1] += c->recv.len;
+    // MG_DEBUG(("Got chunk len %lu, %lu total", c->recv.len, data[1]));
+    c->recv.len = 0;  // Delete received data
+    if (data[1] >= data[0]) {
+      // Uploaded everything. Send response back
+      MG_INFO(("Uploaded %lu bytes", data[1]));
+      mg_http_reply(c, 200, NULL, "%lu ok\n", data[1]);
+      c->is_draining = 1;  // Close us when response gets sent
     }
   }
-  (void) ev_data;
+}
+
+static void fn(struct mg_connection *c, int ev, void *ev_data) {
+  handle_uploads(c, ev, ev_data);
+
+  // Non-upload requests, we serve normally
+  if (ev == MG_EV_HTTP_MSG) {
+    struct mg_http_serve_opts opts = {.root_dir = "web_root"};
+    mg_http_serve_dir(c, ev_data, &opts);
+  }
 }
 
 int main(void) {
   struct mg_mgr mgr;
 
   mg_mgr_init(&mgr);
   mg_log_set(MG_LL_DEBUG);  // Set debug log level
-  mg_listen(&mgr, "http://localhost:8000", fn, NULL);
+  mg_http_listen(&mgr, "http://localhost:8000", fn, NULL);
 
   for (;;) mg_mgr_poll(&mgr, 50);
   mg_mgr_free(&mgr);

mongoose.c

@@ -3219,8 +3219,9 @@ static void http_cb(struct mg_connection *c, int ev, void *ev_data) {
         c->recv.len = 0;
         return;
       }
-      if (n == 0) break;        // Request is not buffered yet
-      if (ev == MG_EV_CLOSE) {  // If client did not set Content-Length
+      if (n == 0) break;                 // Request is not buffered yet
+      mg_call(c, MG_EV_HTTP_HDRS, &hm);  // Got all HTTP headers
+      if (ev == MG_EV_CLOSE) {           // If client did not set Content-Length
         hm.message.len = c->recv.len - ofs;  // and closes now, deliver MSG
         hm.body.len = hm.message.len - (size_t) (hm.body.ptr - hm.message.ptr);
       }
@@ -3237,7 +3238,7 @@ static void http_cb(struct mg_connection *c, int ev, void *ev_data) {
         bool is_response = mg_ncasecmp(hm.method.ptr, "HTTP/", 5) == 0;
         bool require_content_len = false;
         if (!is_response && (mg_vcasecmp(&hm.method, "POST") == 0 ||
-            mg_vcasecmp(&hm.method, "PUT") == 0)) {
+                             mg_vcasecmp(&hm.method, "PUT") == 0)) {
           // POST and PUT should include an entity body. Therefore, they should
           // contain a Content-length header. Other requests can also contain a
           // body, but their content has no defined semantics (RFC 7231)

mongoose.h

@@ -2113,7 +2113,8 @@ enum {
   MG_EV_READ,       // Data received from socket    long *bytes_read
   MG_EV_WRITE,      // Data written to socket       long *bytes_written
   MG_EV_CLOSE,      // Connection closed            NULL
-  MG_EV_HTTP_MSG,   // HTTP request/response        struct mg_http_message *
+  MG_EV_HTTP_HDRS,  // HTTP headers                 struct mg_http_message *
+  MG_EV_HTTP_MSG,   // Full HTTP request/response   struct mg_http_message *
   MG_EV_WS_OPEN,    // Websocket handshake done     struct mg_http_message *
   MG_EV_WS_MSG,     // Websocket msg, text or bin   struct mg_ws_message *
   MG_EV_WS_CTL,     // Websocket control msg        struct mg_ws_message *

src/event.h

@@ -17,7 +17,8 @@ enum {
   MG_EV_READ,       // Data received from socket    long *bytes_read
   MG_EV_WRITE,      // Data written to socket       long *bytes_written
   MG_EV_CLOSE,      // Connection closed            NULL
-  MG_EV_HTTP_MSG,   // HTTP request/response        struct mg_http_message *
+  MG_EV_HTTP_HDRS,  // HTTP headers                 struct mg_http_message *
+  MG_EV_HTTP_MSG,   // Full HTTP request/response   struct mg_http_message *
   MG_EV_WS_OPEN,    // Websocket handshake done     struct mg_http_message *
   MG_EV_WS_MSG,     // Websocket msg, text or bin   struct mg_ws_message *
   MG_EV_WS_CTL,     // Websocket control msg        struct mg_ws_message *

src/http.c

@@ -1003,8 +1003,9 @@ static void http_cb(struct mg_connection *c, int ev, void *ev_data) {
         c->recv.len = 0;
         return;
       }
-      if (n == 0) break;        // Request is not buffered yet
-      if (ev == MG_EV_CLOSE) {  // If client did not set Content-Length
+      if (n == 0) break;                 // Request is not buffered yet
+      mg_call(c, MG_EV_HTTP_HDRS, &hm);  // Got all HTTP headers
+      if (ev == MG_EV_CLOSE) {           // If client did not set Content-Length
         hm.message.len = c->recv.len - ofs;  // and closes now, deliver MSG
         hm.body.len = hm.message.len - (size_t) (hm.body.ptr - hm.message.ptr);
       }
@@ -1021,7 +1022,7 @@ static void http_cb(struct mg_connection *c, int ev, void *ev_data) {
         bool is_response = mg_ncasecmp(hm.method.ptr, "HTTP/", 5) == 0;
         bool require_content_len = false;
         if (!is_response && (mg_vcasecmp(&hm.method, "POST") == 0 ||
-            mg_vcasecmp(&hm.method, "PUT") == 0)) {
+                             mg_vcasecmp(&hm.method, "PUT") == 0)) {
           // POST and PUT should include an entity body. Therefore, they should
           // contain a Content-length header. Other requests can also contain a
           // body, but their content has no defined semantics (RFC 7231)