util.httpstream: Initial commit of the new HTTP parser.

1 files changed, 89 insertions, 0 deletions

diff --git a/util/httpstream.lua b/util/httpstream.lua
new file mode 100644
index 00000000..09116e67
--- /dev/null
+++ b/util/httpstream.lua
@@ -0,0 +1,89 @@
+
+local setmetatable = setmetatable;
+local coroutine = coroutine;
+local tonumber = tonumber;
+
+local print = print;
+local error = error;
+local ser = require "util.serialization".serialize;
+
+local deadroutine = coroutine.create(function() end);
+coroutine.resume(deadroutine);
+
+module("httpstream")
+
+local function parser(data, success_cb)
+	local function readline()
+		if not data then coroutine.yield("Unexpected EOF"); end
+		local pos, line = (data:find("\r\n", nil, true));
+		if not pos then
+			local newdata = coroutine.yield();
+			if not newdata then data = nil; coroutine.yield("Unexpected EOF"); end
+			data = data..newdata;
+			return readline();
+		end
+		line, data = data:sub(1, pos-1), data:sub(pos+2);
+		return line;
+	end
+	local function readlength(n)
+		if not data then coroutine.yield("Unexpected EOF"); end
+		while #data < n do
+			local newdata = coroutine.yield();
+			if not newdata then data = nil; coroutine.yield("Unexpected EOF"); end
+			data = data..newdata;
+		end
+		local r = data:sub(1, n);
+		data = data:sub(n + 1);
+		return r;
+	end
+	
+	while true do
+		-- read status line
+		local status_line = readline();
+		local method, path, httpversion = status_line:match("^(%S+)%s+(%S+)%s+HTTP/(%S+)$");
+		if not method then coroutine.yield("invalid-status-line"); end
+		-- TODO parse url
+		
+		local headers = {}; -- read headers
+		while true do
+			local line = readline();
+			if line == "" then break; end -- headers done
+			local key, val = line:match("^([^%s:]+): *(.*)$");
+			if not key then coroutine.yield("invalid-header-line"); end -- TODO handle multi-line and invalid headers
+			key = key:lower();
+			headers[key] = headers[key] and headers[key]..","..val or val;
+		end
+		
+		-- read body
+		local len = tonumber(headers["content-length"]);
+		len = len or 0; -- TODO check for invalid len
+		local body = readlength(len);
+		
+		success_cb({
+			method = method;
+			path = path;
+			httpversion = httpversion;
+			headers = headers;
+			body = body;
+		});
+	end
+end
+
+function new(success_cb, error_cb)
+	local co = coroutine.create(parser);
+	return {
+		feed = function(self, data)
+			local success, result = coroutine.resume(co, data, success_cb);
+			if result then
+				if result.method then
+					success_cb(result);
+				else -- error
+					error_cb(result);
+					co = deadroutine;
+				end
+			end
+		end;
+	};
+end
+
+return _M;