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author | Indrajith K L | 2022-12-03 17:00:20 +0530 |
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committer | Indrajith K L | 2022-12-03 17:00:20 +0530 |
commit | f5c4671bfbad96bf346bd7e9a21fc4317b4959df (patch) | |
tree | 2764fc62da58f2ba8da7ed341643fc359873142f /v_windows/v/vlib/vweb/sse | |
download | cli-tools-windows-f5c4671bfbad96bf346bd7e9a21fc4317b4959df.tar.gz cli-tools-windows-f5c4671bfbad96bf346bd7e9a21fc4317b4959df.tar.bz2 cli-tools-windows-f5c4671bfbad96bf346bd7e9a21fc4317b4959df.zip |
Diffstat (limited to 'v_windows/v/vlib/vweb/sse')
-rw-r--r-- | v_windows/v/vlib/vweb/sse/sse.v | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/v_windows/v/vlib/vweb/sse/sse.v b/v_windows/v/vlib/vweb/sse/sse.v new file mode 100644 index 0000000..986c618 --- /dev/null +++ b/v_windows/v/vlib/vweb/sse/sse.v @@ -0,0 +1,77 @@ +module sse + +import net +import time +import strings + +// This module implements the server side of `Server Sent Events`. +// See https://developer.mozilla.org/en-US/docs/Web/API/Server-sent_events/Using_server-sent_events#event_stream_format +// as well as https://html.spec.whatwg.org/multipage/server-sent-events.html#server-sent-events +// for detailed description of the protocol, and a simple web browser client example. +// +// > Event stream format +// > The event stream is a simple stream of text data which must be encoded using UTF-8. +// > Messages in the event stream are separated by a pair of newline characters. +// > A colon as the first character of a line is in essence a comment, and is ignored. +// > Note: The comment line can be used to prevent connections from timing out; +// > a server can send a comment periodically to keep the connection alive. +// > +// > Each message consists of one or more lines of text listing the fields for that message. +// > Each field is represented by the field name, followed by a colon, followed by the text +// > data for that field's value. + +[heap] +pub struct SSEConnection { +pub mut: + headers map[string]string + conn &net.TcpConn + write_timeout time.Duration = 600 * time.second +} + +pub struct SSEMessage { + id string + event string + data string + retry int +} + +pub fn new_connection(conn &net.TcpConn) &SSEConnection { + return &SSEConnection{ + conn: unsafe { conn } + } +} + +// sse_start is used to send the start of a Server Side Event response. +pub fn (mut sse SSEConnection) start() ? { + sse.conn.set_write_timeout(sse.write_timeout) + mut start_sb := strings.new_builder(512) + start_sb.write_string('HTTP/1.1 200') + start_sb.write_string('\r\nConnection: keep-alive') + start_sb.write_string('\r\nCache-Control: no-cache') + start_sb.write_string('\r\nContent-Type: text/event-stream') + for k, v in sse.headers { + start_sb.write_string('\r\n$k: $v') + } + start_sb.write_string('\r\n') + sse.conn.write(start_sb) or { return error('could not start sse response') } +} + +// send_message sends a single message to the http client that listens for SSE. +// It does not close the connection, so you can use it many times in a loop. +pub fn (mut sse SSEConnection) send_message(message SSEMessage) ? { + mut sb := strings.new_builder(512) + if message.id != '' { + sb.write_string('id: $message.id\n') + } + if message.event != '' { + sb.write_string('event: $message.event\n') + } + if message.data != '' { + sb.write_string('data: $message.data\n') + } + if message.retry != 0 { + sb.write_string('retry: $message.retry\n') + } + sb.write_string('\n') + sse.conn.write(sb) ? +} |