From fa8f6fac5877020d377e7b58b56b7338ca70993a Mon Sep 17 00:00:00 2001
From: Matthias Ringwald <matthias@ringwald.ch>
Date: Sat, 9 Nov 2019 23:16:53 +0100
Subject: [PATCH] pan_lwip_http_server: serve test file for /NumberOfBytes.txt

---
 .../core/src/include/lwip/apps/httpd_opts.h   |  6 +-
 example/pan_lwip_http_server.c                | 87 +++++++++++++++++++
 2 files changed, 90 insertions(+), 3 deletions(-)

diff --git a/3rd-party/lwip/core/src/include/lwip/apps/httpd_opts.h b/3rd-party/lwip/core/src/include/lwip/apps/httpd_opts.h
index 573eb86ce..78e1308a3 100644
--- a/3rd-party/lwip/core/src/include/lwip/apps/httpd_opts.h
+++ b/3rd-party/lwip/core/src/include/lwip/apps/httpd_opts.h
@@ -178,7 +178,7 @@
  * the (readonly) fsdata will grow a bit as every file includes the HTTP
  * header. */
 #if !defined LWIP_HTTPD_DYNAMIC_HEADERS || defined __DOXYGEN__
-#define LWIP_HTTPD_DYNAMIC_HEADERS 0
+#define LWIP_HTTPD_DYNAMIC_HEADERS 1
 #endif
 
 #if !defined HTTPD_DEBUG || defined __DOXYGEN__
@@ -357,7 +357,7 @@
  *    Called to free resources allocated by fs_open_custom().
  */
 #if !defined LWIP_HTTPD_CUSTOM_FILES || defined __DOXYGEN__
-#define LWIP_HTTPD_CUSTOM_FILES       0
+#define LWIP_HTTPD_CUSTOM_FILES       1
 #endif
 
 /** Set this to 1 to support fs_read() to dynamically read file data.
@@ -365,7 +365,7 @@
  * and the contents must be ready after fs_open().
  */
 #if !defined LWIP_HTTPD_DYNAMIC_FILE_READ || defined __DOXYGEN__
-#define LWIP_HTTPD_DYNAMIC_FILE_READ  0
+#define LWIP_HTTPD_DYNAMIC_FILE_READ  1
 #endif
 
 /** Set this to 1 to include an application state argument per file
diff --git a/example/pan_lwip_http_server.c b/example/pan_lwip_http_server.c
index 2e8c53264..acadec515 100644
--- a/example/pan_lwip_http_server.c
+++ b/example/pan_lwip_http_server.c
@@ -58,6 +58,7 @@
  // *****************************************************************************
 
 #include <stdio.h>
+#include <inttypes.h>
 
 #include "btstack_config.h"
 #include "bnep_lwip.h"
@@ -66,9 +67,17 @@
 #include "lwip/init.h"
 #include "lwip/opt.h"
 #include "lwip/tcpip.h"
+#include "lwip/apps/fs.h"
 #include "lwip/apps/httpd.h"
 #include "dhserver.h"
 
+#if !LWIP_HTTPD_CUSTOM_FILES
+#error This needs LWIP_HTTPD_CUSTOM_FILES
+#endif
+#if !LWIP_HTTPD_DYNAMIC_HEADERS
+#error This needs LWIP_HTTPD_DYNAMIC_HEADERS
+#endif
+
 // network types
 #define NETWORK_TYPE_IPv4       0x0800
 #define NETWORK_TYPE_ARP        0x0806
@@ -217,6 +226,84 @@ static dhcp_config_t dhcp_config =
 /* LISTING_END */
 
 
+/* @section Large File Download
+ *
+ * @text Listing LargeFile Shows how a configurable test file for performance tests is generated on the fly.
+ *       The filename is the number of bytes to generate, e.g. /1048576.txt results in a 1MB file.
+ */
+
+/* LISTING_START(LargeFile): Provide large file. */
+
+int fs_open_custom(struct fs_file *file, const char *name){
+    if (*name != '/') return 0;
+    uint32_t file_size = btstack_atoi(&name[1]);
+    if (file_size > 0) {
+        printf("Serving '%s' with %u bytes\n", name, file_size);
+        /* initialize fs_file correctly */
+        memset(file, 0, sizeof(struct fs_file));
+        file->len = file_size;
+        file->index = 0;
+        file->flags = FS_FILE_FLAGS_HEADER_PERSISTENT;
+        return 1;
+    }
+    return 0;
+}
+
+static uint16_t cgi_buffer_fill(char * cgi_buffer, uint16_t cgi_buffer_size, uint32_t start_pos){
+    // fill buffer with dots
+    memset(cgi_buffer, (uint8_t) '.', cgi_buffer_size);
+    uint16_t cursor = 10;
+    uint16_t pos = 0;
+    const uint16_t line_length = 64;
+
+    while  ((pos + line_length ) < cgi_buffer_size){
+        // write position
+        sprintf((char *) &cgi_buffer[pos], "%08"PRIx32, start_pos + pos);
+        cgi_buffer[pos + 8] = '-';
+        // cursor
+        cgi_buffer[pos+cursor] = '+';
+        cursor++;
+        // new line
+        cgi_buffer[pos+line_length-1] = '\n';
+        pos += line_length;
+    }
+
+    // handle last incomplete line
+    if (pos == 0){
+        const char * last_line_text = "Thank you for evaluating BTstack!";
+        uint16_t bytes_to_copy = btstack_min(strlen(last_line_text), cgi_buffer_size);
+        memcpy(cgi_buffer, last_line_text, bytes_to_copy);
+        pos = cgi_buffer_size;
+    }
+
+    return pos;
+}
+
+int fs_read_custom(struct fs_file *file, char *buffer, int count)
+{
+    uint32_t remaining_data = file->len - file->index;
+    if (remaining_data == 0) {
+        // all bytes already read
+        return FS_READ_EOF;
+    }
+
+    uint32_t bytes_to_fill = remaining_data;
+    if (bytes_to_fill > count){
+        bytes_to_fill = count;
+    }
+
+    uint32_t bytes_written = cgi_buffer_fill(buffer, bytes_to_fill, file->index);
+    file->index += bytes_written;
+
+    return bytes_written;
+}
+
+void
+fs_close_custom(struct fs_file *file){
+}
+
+/* LISTING_END */
+
 /* @section DHCP Server Setup
  *
  * @text Listing LwipSetup shows the setup of the lwIP network stack and starts the DHCP Server