Add an example for event logging

Author: kmcallister

Cargo.toml

@@ -5,6 +5,9 @@ version = "0.0.0"
 authors = [ "The Servo Project Developers" ]
 
 [features]
+
+# Enable event logging for generating benchmark traces.
+# See examples/event-log.
 log-events = []
 
 [dependencies.string_cache_macros]

examples/event-log/Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+
+name = "string-cache-event-log-example"
+version = "0.0.0"
+authors = [ "The Servo Project Developers" ]
+
+[dependencies.string_cache]
+git = "https://github.com/servo/string-cache"
+features = ["log-events"]

examples/event-log/README.md

@@ -0,0 +1,4 @@
+string-cache can record logs of what it's doing, which can be useful for
+guiding future changes to the library.  This project demonstrates how to build
+string-cache with logging enabled (see `Cargo.toml`), and how to access the log
+at runtime.

examples/event-log/src/main.rs

@@ -0,0 +1,31 @@
+// Copyright 2014 The Servo Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+extern crate string_cache;
+
+use string_cache::Atom;
+use string_cache::event;
+
+use std::io;
+
+fn main() {
+    println!("Reading stdin to end of file");
+    let stdin = io::stdin().read_to_string().unwrap();
+    let mut atoms = vec![];
+    for word in stdin.as_slice().split(|c: char| c.is_whitespace()) {
+        atoms.push(Atom::from_slice(word));
+    }
+
+    let log = event::LOG.lock();
+
+    println!("Created {:u} atoms, logged {:u} events:", atoms.len(), log.len());
+    for e in log.iter() {
+        println!("{}", e);
+    }
+}