rust/src/libstd/logging.rs, branch try

log: Introduce liblog, the old std::logging

2014-03-16T05:26:36+00:00

This commit moves all logging out of the standard library into an external crate. This crate is the new crate which is responsible for all logging macros and logging implementation. A few reasons for this change are: * The crate map has always been a bit of a code smell among rust programs. It has difficulty being loaded on almost all platforms, and it's used almost exclusively for logging and only logging. Removing the crate map is one of the end goals of this movement. * The compiler has a fair bit of special support for logging. It has the __log_level() expression as well as generating a global word per module specifying the log level. This is unfairly favoring the built-in logging system, and is much better done purely in libraries instead of the compiler itself. * Initialization of logging is much easier to do if there is no reliance on a magical crate map being available to set module log levels. * If the logging library can be written outside of the standard library, there's no reason that it shouldn't be. It's likely that we're not going to build the highest quality logging library of all time, so third-party libraries should be able to provide just as high-quality logging systems as the default one provided in the rust distribution. With a migration such as this, the change does not come for free. There are some subtle changes in the behavior of liblog vs the previous logging macros: * The core change of this migration is that there is no longer a physical log-level per module. This concept is still emulated (it is quite useful), but there is now only a global log level, not a local one. This global log level is a reflection of the maximum of all log levels specified. The previously generated logging code looked like: if specified_level <= __module_log_level() { println!(...) } The newly generated code looks like: if specified_level <= ::log::LOG_LEVEL { if ::log::module_enabled(module_path!()) { println!(...) } } Notably, the first layer of checking is still intended to be "super fast" in that it's just a load of a global word and a compare. The second layer of checking is executed to determine if the current module does indeed have logging turned on. This means that if any module has a debug log level turned on, all modules with debug log levels get a little bit slower (they all do more expensive dynamic checks to determine if they're turned on or not). Semantically, this migration brings no change in this respect, but runtime-wise, this will have a perf impact on some code. * A `RUST_LOG=::help` directive will no longer print out a list of all modules that can be logged. This is because the crate map will no longer specify the log levels of all modules, so the list of modules is not known. Additionally, warnings can no longer be provided if a malformed logging directive was supplied. The new "hello world" for logging looks like: #[phase(syntax, link)] extern crate log; fn main() { debug!("Hello, world!"); }

std: Switch stdout/stderr to buffered by default

2014-03-01T18:06:20+00:00

Similarly to #12422 which made stdin buffered by default, this commit makes the output streams also buffered by default. Now that buffered writers will flush their contents when they are dropped, I don't believe that there's no reason why the output shouldn't be buffered by default, which is what you want in 90% of cases. As with stdin, there are new stdout_raw() and stderr_raw() functions to get unbuffered streams to stdout/stderr.

Move std::{trie, hashmap} to libcollections

2014-02-23T08:35:11+00:00

These two containers are indeed collections, so their place is in libcollections, not in libstd. There will always be a hash map as part of the standard distribution of Rust, but by moving it out of the standard library it makes libstd that much more portable to more platforms and environments. This conveniently also removes the stuttering of 'std::hashmap::HashMap', although 'collections::HashMap' is only one character shorter.

Fix all code examples

2014-02-15T07:49:22+00:00

Move replace and swap to std::mem. Get rid of std::util

2014-02-10T21:21:35+00:00

Also move Void to std::any, move drop to std::mem and reexport in prelude.

std: Remove io::io_error

2014-02-03T17:32:33+00:00

* All I/O now returns IoResult = Result * All formatting traits now return fmt::Result = IoResult<()> * The if_ok!() macro was added to libstd

Tweak the interface of std::io

2014-01-17T18:00:47+00:00

* Reexport io::mem and io::buffered structs directly under io, make mem/buffered private modules * Remove with_mem_writer * Remove DEFAULT_CAPACITY and use DEFAULT_BUF_SIZE (in io::buffered)

Support arbitrary stdout/stderr/logger handles

2014-01-06T21:19:53+00:00

This will allow capturing of common things like logging messages, stdout prints (using stdio println), and failure messages (printed to stderr). Any new prints added to libstd should be funneled through these task handles to allow capture as well. Additionally, this commit redirects logging back through a `Logger` trait so the log level can be usefully consumed by an arbitrary logger. This commit also introduces methods to set the task-local stdout handles: * std::io::stdio::set_stdout * std::io::stdio::set_stderr * std::io::logging::set_logger These methods all return the previous logger just in case it needs to be used for inspection. I plan on using this infrastructure for extra::test soon, but we don't quite have the primitives that I'd like to use for it, so it doesn't migrate extra::test at this time. Closes #6369

std: uniform modules titles for doc

2013-12-27T08:49:11+00:00

This commit uniforms the short title of modules provided by libstd, in order to make their roles more explicit when glancing at the index. Signed-off-by: Luca Bruno

std: Make logging safely implemented

2013-12-24T22:42:00+00:00

This commit fixes the logging function to be safely implemented, as well as forcibly requiring a task to be present to use logging macros. This is safely implemented by transferring ownership of the logger from the task to the local stack frame in order to perform the print. This means that if a logger does more logging while logging a new one will be initialized and then will get overwritten once the initial logging function returns. Without a scheme such as this, it is possible to unsafely alias two loggers by logging twice (unsafely borrows from the task twice).