feat: only memmove read buffer on read

include/http.h

@@ -34,6 +34,7 @@ typedef enum http_parse_error {
   http_parse_error_invalid = 2,
 } http_parse_error;
 
-http_parse_error http_parse_request(http_request *req, const char *path, size_t path_len);
+http_parse_error http_parse_request(http_request *req, const char *path,
+                                    size_t path_len);
 
 #endif

src/event_loop/event_loop_conn.c

@@ -11,6 +11,7 @@
 #include <unistd.h>
 
 #include "picohttpparser.h"
+#include "http.h"
 
 #include "event_loop_internal.h"
 
@@ -54,7 +55,7 @@ void event_loop_conn_io_res(event_loop_conn *conn) {
 bool event_loop_handle_request(event_loop_conn *conn) {
   // Prevents the request handler function from looping indefinitely without
   // ever consuming new data
-  if (conn->rbuf_size == 0) {
+  if (conn->rbuf_size - conn->rbuf_read == 0) {
     return false;
   }
 
@@ -69,7 +70,7 @@ bool event_loop_handle_request(event_loop_conn *conn) {
 
   num_headers = sizeof(headers) / sizeof(headers[0]);
 
-  int res = phr_parse_request((const char *)conn->rbuf, conn->rbuf_size,
+  int res = phr_parse_request((const char *)&conn->rbuf[conn->rbuf_read], conn->rbuf_size - conn->rbuf_read,
                               &method, &method_len, &path, &path_len,
                               &minor_version, headers, &num_headers, 0);
 
@@ -77,27 +78,33 @@ bool event_loop_handle_request(event_loop_conn *conn) {
     /* for (size_t i = 0; i < num_headers; i++) { */
     /*   /1* printf("%.*s: ", headers[i].name_len, headers[i].name); *1/ */
     /*   /1* printf("%.*s\n", headers[i].value_len, headers[i].value); *1/ */
-    /*   if (strncmp("Connection", headers[i].name, headers[i].name_len) == 0) { */
+    /*   if (strncmp("Connection", headers[i].name, headers[i].name_len) == 0) {
-    /*     if (strncmp("close", headers[i].value, headers[i].value_len) == 0) { */
+     */
+    /*     if (strncmp("close", headers[i].value, headers[i].value_len) == 0) {
+     */
     /*       conn->close_after_write = true; */
     /*       break; */
     /*     } */
     /*   } */
     /* } */
 
-    /* memcpy(conn->wbuf, http_500, http_500_len); */
+    // Advance the read buffer
+    conn->rbuf_read += res;
 
-    /* // Move the new request up to the front of the read buffer */
+    memcpy(conn->wbuf, http_404, http_404_len);
+
+    // Move the new request up to the front of the read buffer
     /* memmove(conn->rbuf, &conn->rbuf[res], conn->rbuf_size - res); */
     /* conn->rbuf_size -= res; */
 
-    /* conn->state = event_loop_conn_state_res; */
+    conn->state = event_loop_conn_state_res;
-    /* conn->wbuf_size = http_500_len; */
+    conn->wbuf_size = http_404_len;
-    /* conn->wbuf_sent = 0; */
+    conn->wbuf_sent = 0;
 
-    /* /1* event_loop_conn_io_res(conn); *1/ */
+    event_loop_conn_io_res(conn);
 
-    /* // End the connection if the http request is invalid, or when the response */
+    /* // End the connection if the http request is invalid, or when the
+     * response */
     /* // is too large to fit into a single read buffer */
   } else if (res == -1 ||
              (res == -2 && conn->rbuf_size == EVENT_LOOP_BUFFER_SIZE)) {
@@ -114,7 +121,12 @@ bool event_loop_handle_request(event_loop_conn *conn) {
  * Returns whether the function should be retried immediately or not.
  */
 void event_loop_conn_io_req(event_loop_conn *conn) {
-  while (1) {
+  do {
+    // Move remaining data to start of buffer
+    memmove(conn->rbuf, &conn->rbuf[conn->rbuf_read], conn->rbuf_size - conn->rbuf_read);
+    conn->rbuf_size -= conn->rbuf_read;
+    conn->rbuf_read = 0;
+
     ssize_t res;
     size_t cap = EVENT_LOOP_BUFFER_SIZE - conn->rbuf_size;
 
@@ -153,19 +165,12 @@ void event_loop_conn_io_req(event_loop_conn *conn) {
 
     conn->rbuf_size += (size_t)res;
 
-    /* assert(conn->rbuf_size <= sizeof(conn->rbuf)); */
+    // This loop allows processing multiple requests from a single read buffer
-
+    while (event_loop_handle_request(conn))
-    // Try to process requests one by one.
+      ;
-    // Try to process requests one by one.
-    // Why is there a loop? Please read the explanation of "pipelining".
-    while (event_loop_handle_request(conn)) {
-    };
-
-    // We can keep reading as long as we're in request mode
-    if (conn->state != event_loop_conn_state_req) {
-      return;
-    };
   }
+  // We can keep reading as long as we're in request mode
+  while (conn->state == event_loop_conn_state_req);
 }
 
 void event_loop_conn_io(event_loop_conn *conn) {

src/event_loop/event_loop_internal.h

@@ -12,6 +12,7 @@ typedef struct event_loop_conn {
   event_loop_conn_state state;
   // buffer for reading
   size_t rbuf_size;
+  size_t rbuf_read;
   uint8_t rbuf[EVENT_LOOP_BUFFER_SIZE];
   // buffer for writing
   size_t wbuf_size;

src/http/http_parse.c

@@ -4,16 +4,17 @@
 /*
  * given the HTTP path, parse the request
  */
-http_parse_error http_parse_request(http_request *req, const char *buf, size_t buf_size) {
+http_parse_error http_parse_request(http_request *req, const char *buf,
+                                    size_t buf_size) {
   // First we try to parse the incoming HTTP request
   const char *method, *path;
   struct phr_header headers[16];
   size_t method_len, path_len, num_headers;
   int minor_version;
 
-  int res = phr_parse_request(buf, buf_size,
+  int res =
-                              &method, &method_len, &path, &path_len,
+      phr_parse_request(buf, buf_size, &method, &method_len, &path, &path_len,
-                              &minor_version, headers, &num_headers, 0);
+                        &minor_version, headers, &num_headers, 0);
 
   if (res == -2) {
     return http_parse_error_incomplete;