From e4d95f5dc937bf549e7436a3c33ca3db9dcff185 Mon Sep 17 00:00:00 2001
From: Falk Werner <falk.werner@gmx.net>
Date: Sun, 3 Mar 2019 18:02:30 +0100
Subject: [PATCH] implements operation read

---
 example/provider/main.c            | 30 +++++++++++---
 lib/wsfs/provider/operation/read.c | 63 ++++++++++++++++++++++++++----
 2 files changed, 80 insertions(+), 13 deletions(-)

diff --git a/example/provider/main.c b/example/provider/main.c
index 15f7b94..4cc21e1 100644
--- a/example/provider/main.c
+++ b/example/provider/main.c
@@ -203,6 +203,11 @@ static void fs_open(
     }
 }
 
+static size_t min(size_t const a, size_t const b)
+{
+    return (a < b) ? a : b;
+}
+
 static void fs_read(
     struct wsfsp_request * request,
     ino_t inode,
@@ -211,13 +216,28 @@ static void fs_read(
     size_t length,
     void * user_data)
 {
-    (void) inode;
     (void) handle;
-    (void) offset;
-    (void) length;
-    (void) user_data;
 
-    wsfsp_respond_error(request, -1);
+    struct fs * fs = (struct fs*) user_data;
+    struct fs_entry const * entry = fs_getentry(fs, inode);
+    if ((NULL != entry) && (FS_FILE == entry->type))
+    {
+        if (entry->content_length > offset)
+        {
+            size_t const remaining = entry->content_length - offset;
+            size_t const count = min(remaining, length);
+
+            wsfsp_respond_read(request, &entry->content[offset], count);
+        }
+        else
+        {
+            wsfsp_respond_error(request, -1);
+        }        
+    }
+    else
+    {
+        wsfsp_respond_error(request, -1);
+    }
 }
 
 static struct wsfsp_provider fs_provider =
diff --git a/lib/wsfs/provider/operation/read.c b/lib/wsfs/provider/operation/read.c
index ac802d8..c7e4fec 100644
--- a/lib/wsfs/provider/operation/read.c
+++ b/lib/wsfs/provider/operation/read.c
@@ -1,5 +1,8 @@
 #include "wsfs/provider/operation/read_intern.h"
-#include <stdio.h>
+
+#include <stdlib.h>
+#include <libwebsockets.h>
+
 #include "wsfs/provider/operation/error.h"
 #include "wsfs/util.h"
 
@@ -8,11 +11,28 @@ void wsfsp_read(
     json_t * params,
     int id)
 {
-    (void) context;
-    (void) params;
-    (void) id;
+    size_t const count = json_array_size(params);
+    if (4 == count)
+    {
+        json_t * inode_holder = json_array_get(params, 0);
+        json_t * handle_holder = json_array_get(params, 1);
+        json_t * offset_holder = json_array_get(params, 2);
+        json_t * length_holder = json_array_get(params, 3);
+
+        if (json_is_integer(inode_holder) &&
+            json_is_integer(handle_holder) &&
+            json_is_integer(offset_holder) &&
+            json_is_integer(length_holder))
+        {
+            ino_t inode = (ino_t) json_integer_value(inode_holder);
+            int handle = json_integer_value(handle_holder);
+            size_t offset = json_integer_value(offset_holder);
+            size_t length = json_integer_value(length_holder);
+            struct wsfsp_request * request = wsfsp_request_create(context->request, id);
 
-    puts("read");  
+            context->provider->read(request, inode, handle, offset, length, context->user_data);
+        }
+    } 
 }
 
 void wsfsp_read_default(
@@ -31,7 +51,34 @@ void wsfsp_respond_read(
     char const * data,
     size_t length)
 {
-    (void) request;
-    (void) data;
-    (void) length;
+    if (0 < length)
+    {
+        size_t const size = 4 * ((length / 3) + 2);
+        char * buffer = malloc(size);
+        if (NULL != buffer)
+        {
+            lws_b64_encode_string(data, length, buffer, size);
+
+            json_t * result = json_object();
+            json_object_set_new(result, "data", json_string(buffer));
+            json_object_set_new(result, "format", json_string("base64"));
+            json_object_set_new(result, "count", json_integer((int) length));
+
+            wsfsp_respond(request, result);
+            free(buffer);
+        }
+        else
+        {
+            wsfsp_respond_error(request, -1);
+        }
+    }
+    else
+    {
+            json_t * result = json_object();
+            json_object_set_new(result, "data", json_string(""));
+            json_object_set_new(result, "format", json_string("identitiy"));
+            json_object_set_new(result, "count", json_integer(0));
+
+            wsfsp_respond(request, result);        
+    }
 }
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