1# Change Log
2
3## [Unreleased]
4
5## [0.4.8] - 2019-07-28
6
7### New
8
9* Support attempting to get `Record` fields as static strings.
10
11## [0.4.7] - 2019-07-06
12
13### New
14
15* Support for embedded environments with thread-unsafe initialization.
16* Initial unstable support for capturing structured data under the `kv_unstable`
17feature gate. This new API doesn't affect existing users and may change in future
18patches (so those changes may not appear in the changelog until it stabilizes).
19
20### Improved
21
22* Docs for using `log` with the 2018 edition.
23* Error messages for macros missing arguments.
24
25## [0.4.6] - 2018-10-27
26
27### Improved
28
29* Support 2018-style macro import for the `log_enabled!` macro.
30
31## [0.4.5] - 2018-09-03
32
33### Improved
34
35* Make `log`'s internal helper macros less likely to conflict with user-defined
36  macros.
37
38## [0.4.4] - 2018-08-17
39
40### Improved
41
42* Support 2018-style imports of the log macros.
43
44## [0.4.3] - 2018-06-29
45
46### Improved
47
48* More code generation improvements.
49
50## [0.4.2] - 2018-06-05
51
52### Improved
53
54* Log invocations now generate less code.
55
56### Fixed
57
58* Example Logger implementations now properly set the max log level.
59
60## [0.4.1] - 2017-12-30
61
62### Fixed
63
64* Some doc links were fixed.
65
66## [0.4.0] - 2017-12-24
67
68The changes in this release include cleanup of some obscure functionality and a more robust public
69API designed to support bridges to other logging systems, and provide more flexibility to new
70features in the future.
71
72### Compatibility
73
74Vast portions of the Rust ecosystem use the 0.3.x release series of log, and we don't want to force
75the community to go through the pain of upgrading every crate to 0.4.x at the exact same time. Along
76with 0.4.0, we've published a new 0.3.9 release which acts as a "shim" over 0.4.0. This will allow
77crates using either version to coexist without losing messages from one side or the other.
78
79There is one caveat - a log message generated by a crate using 0.4.x but consumed by a logging
80implementation using 0.3.x will not have a file name or module path. Applications affected by this
81can upgrade their logging implementations to one using 0.4.x to avoid losing this information. The
82other direction does not lose any information, fortunately!
83
84**TL;DR** Libraries should feel comfortable upgrading to 0.4.0 without treating that as a breaking
85change. Applications may need to update their logging implementation (e.g. env-logger) to a newer
86version using log 0.4.x to avoid losing module and file information.
87
88### New
89
90* The crate is now `no_std` by default.
91* `Level` and `LevelFilter` now implement `Serialize` and `Deserialize` when the `serde` feature is
92    enabled.
93* The `Record` and `Metadata` types can now be constructed by third-party code via a builder API.
94* The `logger` free function returns a reference to the logger implementation. This, along with the
95    ability to construct `Record`s, makes it possible to bridge from another logging framework to
96    this one without digging into the private internals of the crate. The standard `error!` `warn!`,
97    etc, macros now exclusively use the public API of the crate rather than "secret" internal APIs.
98* `Log::flush` has been added to allow crates to tell the logging implementation to ensure that all
99    "in flight" log events have been persisted. This can be used, for example, just before an
100    application exits to ensure that asynchronous log sinks finish their work.
101
102### Removed
103
104* The `shutdown` and `shutdown_raw` functions have been removed. Supporting shutdown significantly
105    complicated the implementation and imposed a performance cost on each logging operation.
106* The `log_panics` function and its associated `nightly` Cargo feature have been removed. Use the
107    [log-panics](https://crates.io/crates/log-panics) instead.
108
109### Changed
110
111* The `Log` prefix has been removed from type names. For example, `LogLevelFilter` is now
112    `LevelFilter`, and `LogRecord` is now `Record`.
113* The `MaxLogLevelFilter` object has been removed in favor of a `set_max_level` free function.
114* The `set_logger` free functions have been restructured. The logger is now directly passed to the
115    functions rather than a closure which returns the logger. `set_logger` now takes a `&'static
116    Log` and is usable in `no_std` contexts in place of the old `set_logger_raw`. `set_boxed_logger`
117    is a convenience function which takes a `Box<Log>` but otherwise acts like `set_logger`. It
118    requires the `std` feature.
119* The `file` and `module_path` values in `Record` no longer have the `'static` lifetime to support
120    integration with other logging frameworks that don't provide a `'static` lifetime for the
121    equivalent values.
122* The `file`, `line`, and `module_path` values in `Record` are now `Option`s to support integration
123    with other logging frameworks that don't provide those values.
124
125### In the Future
126
127* We're looking to add support for *structured* logging - the inclusion of extra key-value pairs of
128    information in a log event in addition to the normal string message. This should be able to be
129    added in a backwards compatible manner to the 0.4.x series when the design is worked out.
130
131## Older
132
133Look at the [release tags] for information about older releases.
134
135[Unreleased]: https://github.com/rust-lang-nursery/log/compare/0.4.8...HEAD
136[0.4.8]: https://github.com/rust-lang-nursery/log/compare/0.4.7...0.4.8
137[0.4.7]: https://github.com/rust-lang-nursery/log/compare/0.4.6...0.4.7
138[0.4.6]: https://github.com/rust-lang-nursery/log/compare/0.4.5...0.4.6
139[0.4.5]: https://github.com/rust-lang-nursery/log/compare/0.4.4...0.4.5
140[0.4.4]: https://github.com/rust-lang-nursery/log/compare/0.4.3...0.4.4
141[0.4.3]: https://github.com/rust-lang-nursery/log/compare/0.4.2...0.4.3
142[0.4.2]: https://github.com/rust-lang-nursery/log/compare/0.4.1...0.4.2
143[0.4.1]: https://github.com/rust-lang-nursery/log/compare/0.4.0...0.4.1
144[0.4.0]: https://github.com/rust-lang-nursery/log/compare/0.3.8...0.4.0
145[release tags]: https://github.com/rust-lang-nursery/log/releases
146