io: add io.streamfile()

3 files changed, 146 insertions, 8 deletions

diff --git a/lem/io.lua b/lem/io.lua
index f123d1e..bd24d66 100644
--- a/lem/io.lua
+++ b/lem/io.lua
@@ -46,11 +46,11 @@ do
 		return stdin:read(...)
 	end
 
-	local open, error = io.open, error
+	local streamfile, error = io.streamfile, error
 	function io.lines(filename, fmt)
 		if not filename then return stdin:lines(fmt) end
 		if not fmt then fmt = '*l' end
-		local file, err = open(filename)
+		local file, err = streamfile(filename)
 		if not file then error(err, 2) end
 		return function(s)
 			local line = s:read(fmt)
diff --git a/lem/io/core.c b/lem/io/core.c
index b5fe4d6..d41c3d0 100644
--- a/lem/io/core.c
+++ b/lem/io/core.c
@@ -318,6 +318,128 @@ error:
 	return io_strerror(T, err);
 }
 
+/*
+ * io.streamfile()
+ */
+struct streamfile {
+	struct lem_async a;
+	const char *filename;
+	int pipe[2];
+	int file;
+};
+
+static void
+io_streamfile_work(struct lem_async *a)
+{
+	struct streamfile *s = (struct streamfile *)a;
+	int file = s->file;
+	int pipe = s->pipe[1];
+
+#ifdef __FreeBSD__
+	sendfile(file, pipe, 0, 0, NULL, NULL, SF_SYNC);
+#else
+#ifdef __APPLE__
+	off_t len = 0;
+	sendfile(file, pipe, 0, &len, NULL, 0);
+#else
+	while (sendfile(pipe, file, NULL, 2147483647) > 0);
+#endif
+#endif
+	close(file);
+	close(pipe);
+}
+
+static void
+io_streamfile_open(struct lem_async *a)
+{
+	struct streamfile *s = (struct streamfile *)a;
+	int file = open(s->filename,
+#ifdef O_CLOEXEC
+			O_CLOEXEC |
+#endif
+			O_RDONLY);
+	if (file < 0) {
+		s->file = -errno;
+		return;
+	}
+#ifndef O_CLOEXEC
+	if (fcntl(file, F_SETFD, FD_CLOEXEC) == -1) {
+		s->file = -errno;
+		goto err1;
+	}
+#endif
+
+	if (socketpair(AF_UNIX,
+#ifdef SOCK_CLOEXEC
+				SOCK_CLOEXEC |
+#endif
+				SOCK_STREAM, 0, s->pipe)) {
+		s->file = -errno;
+		goto err1;
+	}
+	if (
+#ifndef SOCK_CLOEXEC
+			fcntl(s->pipe[1], F_SETFD, FD_CLOEXEC) == -1 ||
+			fcntl(s->pipe[0], F_SETFD, FD_CLOEXEC) == -1 ||
+#endif
+			shutdown(s->pipe[0], SHUT_WR)) {
+		s->file = -errno;
+		goto err2;
+	}
+	if (fcntl(s->pipe[0], F_SETFL, O_NONBLOCK) == -1) {
+		s->file = -errno;
+		goto err2;
+	}
+	s->file = file;
+	return;
+err2:
+	close(s->pipe[0]);
+	close(s->pipe[1]);
+err1:
+	close(file);
+}
+
+static void
+io_streamfile_reap(struct lem_async *a)
+{
+	struct streamfile *s = (struct streamfile *)a;
+	lua_State *T = s->a.T;
+	int ret;
+
+	if (T == NULL) {
+		free(s);
+		return;
+	}
+
+	ret = s->file;
+	if (ret < 0) {
+		free(s);
+		lem_queue(T, io_strerror(T, -ret));
+		return;
+	}
+	lem_debug("s->file = %d, s->pipe[0] = %d, s->pipe[1] = %d",
+			ret, s->pipe[0], s->pipe[1]);
+
+	lem_async_do(&s->a, NULL, io_streamfile_work, io_streamfile_reap);
+
+	stream_new(T, s->pipe[0], 2);
+	lem_queue(T, 1);
+}
+
+static int
+io_streamfile(lua_State *T)
+{
+	const char *filename = lua_tostring(T, 1);
+	struct streamfile *s = lem_xmalloc(sizeof(struct streamfile));
+
+	s->filename = filename;
+	lem_async_do(&s->a, T, io_streamfile_open, io_streamfile_reap);
+
+	lua_settop(T, 1);
+	lua_pushvalue(T, lua_upvalueindex(1));
+	return lua_yield(T, 2);
+}
+
 static void
 push_stdstream(lua_State *L, int fd)
 {
@@ -455,6 +577,10 @@ luaopen_lem_io_core(lua_State *L)
 	lua_getfield(L, -1, "Stream"); /* upvalue 1 = Stream */
 	lua_pushcclosure(L, io_popen, 1);
 	lua_setfield(L, -2, "popen");
+	/* insert streamfile function */
+	lua_getfield(L, -1, "Stream"); /* upvalue 1 = Stream */
+	lua_pushcclosure(L, io_streamfile, 1);
+	lua_setfield(L, -2, "streamfile");
 
 	/* create tcp table */
 	lua_createtable(L, 0, 0);
diff --git a/test/lines.lua b/test/lines.lua
index 2558184..001ff61 100755
--- a/test/lines.lua
+++ b/test/lines.lua
@@ -26,19 +26,31 @@ local io    = require 'lem.io'
 local format, write = string.format, io.write
 
 local n = 0
+
+if not arg[1] then
+   io.stderr:write("I need a file..\n")
+   utils.exit(1)
+end
+
 ---[[
-local file = assert(io.open('PKGBUILD'))
+local file, err = io.streamfile(arg[1])
+--local file, err = io.open(arg[1])
+
+if not file then
+	io.stderr:write(format("Error opening '%s': %s\n", arg[1], err))
+	utils.exit(1)
+end
 
 for line in file:lines() do
    n = n+1
-   write(format("%4d: %s\n", n, line))
 end
 --[=[
 --]]
-for line in io.lines('PKGBUILD') do
-   n = n+1
-   write(format("%4d: %s\n", n, line))
+for line in io.lines(arg[1]) do
+	n = n+1
 end
 --]=]
 
--- vim: syntax=lua ts=3 sw=3 et:
+write(format('%d lines\n', n))
+
+-- vim: syntax=lua ts=2 sw=2 noet: