support decode the multipart form data as lua table

lib/resty/form.lua

@@ -0,0 +1,145 @@
+--[[
+Description:
+    This script is aimed to extend the nginx lua module, to provide support of 
+    decoding HTTP multipart form data into Lua table. 
+    The script requires the upload module, which is from :
+        https://github.com/openresty/lua-resty-upload
+
+FileId:
+$Id: form.lua
+2014-07-09 16:08 星期三
+
+License:
+Copyright 2014, mochui.net, all rights reserved.
+--]]
+
+module("form", package.seeall)
+
+local upload = require "upload";
+
+local function decodeContentDisposition(value)
+    local ret;
+
+    local typ, paras = string.match(value, "([%w%-%._]+);(.+)");
+
+    if typ then
+        ret                 = {};
+        ret.dispositionType = typ;
+        ret.paras           = {};
+
+        if paras then
+            for paraKey, paraValue in string.gmatch(paras, '([%w%.%-_]+)="([^=;]+)"') do
+                -- Fixed, IE <= 8 problem, filename is fullpath, "c:\Users\fuckIE\xx.tar.gz", other borwsers just have a basename "xx.tar.gz".
+                if paraKey == "filename" then
+                    local basename, _ = string.match(paraValue, '[^\\]+$') or ""
+                    paraValue = basename;
+                end
+
+                ret.paras[paraKey] = paraValue;
+            end
+        end
+    end
+
+    return ret;
+end
+
+local function decodeHeaderItem(key, value)
+    local ret;
+
+    if key == "Content-Disposition" then
+        ret = decodeContentDisposition(value);
+    end
+
+    if key == "Content-Type" then
+        ret = value;
+    end
+
+    return ret;
+end
+
+local function decodeHeader(res)
+    if type(res) == "table" and res[1] and res[2] then
+        key     = res[1];
+        value   = decodeHeaderItem(res[1], res[2]);
+    else
+        key     = res;
+        value   = res;
+    end
+
+    return key, value;
+end
+
+function getFormTable(tmpFileFolder)
+    local chunkSize = 4096;
+    local formdata  = {};
+    local part      = {};
+    part.headers    = {};
+    part.body       = "";
+
+    local headers   = {};
+
+    util.log("start to decode form data");
+    local form, err = upload:new(chunkSize);
+    if not form then
+        return nil, err;
+    end
+
+    form:set_timeout(1000);
+
+    while true do
+        local typ, res, err = form:read();
+
+        if not typ then
+            return nil, err;
+        end
+
+        if typ == "header" then
+            local key, value = decodeHeader(res);
+            util.log("header:" .. tostring(res[3]));
+            if key then
+                part.headers[key] = value;
+            else
+                return nil, "failed to decode header:" .. res;
+            end
+        end
+
+        if typ == "body" then
+            if part.headers["Content-Disposition"] 
+                and part.headers["Content-Disposition"].paras
+                and part.headers["Content-Disposition"].paras.filename then    
+                local filePath = tmpFileFolder or "/tmp";
+                local fullFileName = filePath .. "/" 
+                    .. part.headers["Content-Disposition"].paras.filename;
+                if not part.tmpFd then
+                    part.tmpFd, err = io.open(fullFileName, "w");
+                    if not part.tmpFd then
+                        return nil, "failed to open tmpfile:" 
+                                    .. tostring(fullFileName);
+                    end
+                    part.body = fullFileName;
+                end
+                part.tmpFd:write(res);
+            else
+                part.body = part.body .. res;
+            end
+        end
+
+        if typ == "part_end" then
+            if part.tmpFd then
+                part.tmpFd:close();
+            end
+            table.insert(formdata, part);
+            part            = {};
+            part.headers    = {};
+            part.body       = ""; 
+            part.tmpFd      = nil;
+        end
+
+        if typ == "eof" then
+            break;
+        end
+    end
+
+    return formdata, err;
+end
+