CHANGELOG.md

Change log

All notable changes to the LaunchDarkly C SDK will be documented in this file. This project adheres to Semantic Versioning.

[2.5.5] - 2023-02-01

Fixed:

• Fixed GCC 11 compiler diagnostic which prevented compilation using the default CMake configuration on Ubuntu 20.04 (thanks for the report, @yzabalotski!)
• Fixed handling of empty initial PUTs, which might occur if an environment has no flag or segment data.

[2.5.4] - 2023-01-04

Fixed:

• Fixed handling of out-of-order or stale flag updates. These updates are now discarded.
• Fixed serialization of private user attributes array in initial streaming/polling request payload.
• Fixed use-after-free when polling mode was used w/ REPORT method (LDConfigSetUseReport).

[2.5.3] - 2022-12-09

Added:

• Added contract test service.
• Added missing track and alias methods to C++ headers.

Fixed:

• Fixed hang on Windows when LDClientClose was called after internet connection was dropped.
• Fixed incorrect handling of configured URIs that contained trailing slashes.
• Fixed incorrect handling of optional properties in flag data.
• Fixed conversions of timestamps to JSON such that values are always represented as integers.

[2.5.2] - 2022-09-19

Fixed:

• Fixed an issue where LDClientSaveFlags would return null if a flag was archived after initializing the SDK.

[2.5.1] - 2022-08-22

Fixed:

• Fixed an issue where LDAllFlags would return null if a flag was archived after initializing the SDK in streaming mode.

[2.5.0] - 2022-08-01

Added:

• Added LDSetClientStatusCallbackUserData, which allows for passing a void *userData parameter.
• Added documentation on LDClientIdentify, clarifying its asynchronous nature.

Deprecated:

• Deprecated LDSetClientStatusCallback in favor of LDSetClientStatusCallbackUserData. Pass NULL as the user data parameter for equivalent usage.

[2.4.9] - 2022-07-12

Added:

• Added extra debug logging for CURL status codes when network requests fail.

[2.4.8] - 2022-07-06

Fixed:

• Fixes experimentation functionality. If an experiment is running, the SDK should now properly report flag evaluation reasons to the LaunchDarkly backend.

[2.4.7] - 2022-06-29

Fixed:

• Fixed generation of event payload ID header when assertions are disabled.

[2.4.6] - 2022-06-03

Added:

• Added documentation to C++ bindings, available in source and via Doxygen.

Removed:

• Removed redundant const qualifiers in C++ bindings.

[2.4.5] - 2022-05-31

Fixed:

• Fixed deadlock triggered by interaction between LDClientIdentify and background threads. (Thank you, @juancampa.)

[2.4.4] - 2022-03-14

Changed:

• Updated CircleCI configuration with new valgrind/drd jobs.

Fixed:

• Fixed Use-After-Free bug within LDClientUnregisterFeatureFlagListener

[2.4.3] - 2022-02-16

Fixed:

• Fixed uninitialized variable compiler errors when compiled at -O3.
• Fixed streaming connection retry behavior when SDK was unable to resolve remote hostname.

Added:

• Added new CircleCI job to validate -O3 build.

Changed:

• Changed CircleCI macOS executors to Gen2 resource class.

[2.4.2] - 2022-02-01

Fixed:

• Allow macOS 11 build target to compile successfully using macOS 12 host.

[2.4.1] - 2022-01-25

Fixed:

• Fixed build issue on MacOS Monterey 12.1 due to deprecation of a symbol.

[2.4.0] - 2021-12-10

Added:

• Added a new configuration for request timeouts. Use LDConfigSetRequestTimeoutMillis to set the timeout for non-streaming requests. The default timeout is 30 seconds. This includes the total time for the request including connection.
• Added a new method for configuring connection timeouts. LDConfigSetConnectionTimeoutMillis.

Changed:

• Unit tests have been converted to use googletest.

Fixed:

• Fixed an issue where inactive stream connections could remain open indefinitely. Now streams will be closed after 5 minutes of inactivity and the SDK will attempt to establish a new connection.

Deprecated:

• Deprecated LDConfigSetConnectionTimeoutMillies. The LDConfigSetConnectionTimeoutMillis method should be used instead.

[2.3.1] - 2021-07-09

Fixed:

• Add more restrictive build flags and fix warnings

[2.3.0] - 2021-01-26

Added:

• Added the LDClientAlias function. This can be used to associate two user objects for analytics purposes with an alias event.
• Added the LDConfigAutoAliasOptOut function. This can be used to control the new behavior of LDClientIdentify. By passing true LDClientIdentify will not automatically generate alias events.

Changed:

• The LDClientIdentify method will now automatically generate an alias event when switching from an anonymous to a known user. This event associates the two users for analytics purposes as they most likely represent a single person.

Fixed:

• Relaxed internal locking to improve performance.

[2.2.1] - 2021-01-12

Fixed:

• Fixed the IP field of a user object leaking in certain situations
• Fixed the non allocating string variation not respecting result buffer limits
• Minor compiler warnings in MSVC

Added:

• Added code coverage reporting to CMake
• Better unit test coverage

[2.2.0] - 2020-11-24

Added:

• LDBasicLoggerThreadSafeInitialize used to setup LDBasicLoggerThreadSafe
• LDBasicLoggerThreadSafe a thread safe alternative to LDBasicLogger
• LDBasicLoggerThreadSafeShutdown to cleanup LDBasicLoggerThreadSafe resources
• Tests utilizing a mock HTTP server

Fixed:

• Resource cleanup on failed client initialization
• LDConfigSetConnectionTimeoutMillis configuration value being ignored

Deprecated:

• Marked LDBasicLogger as deprecated

[2.1.2] - 2020-11-17

Changed:

• OSX artifacts are now generated with Xcode 9.4.1

Fixed:

• Removed extra internal definition of LDi_statuscallback

[2.1.1] - 2020-08-19

Fixed:

• Create shared library artifacts for linux and mac (fixes #57)

[2.1.0] - 2020-07-28

Added:

• Added LDUserSetCountry. Thanks @mstrater !

[2.0.3] - 2020-07-06

Changed:

• Windows artifacts are now released under both debug, and release configurations

Fixed:

• Windows release artifacts no longer include miscellaneous build files introduced by 2.0.2

[2.0.2] - 2020-07-02

Changed:

• 2.0.0 Accidentally included the debug runtime on Windows. The debug runtime has been removed.

[2.0.1] - 2020-06-18

Changed:

• Update DLLs to include metadata on Windows

Removed:

• Redundant internal logic related to stream cancellation

[2.0.0] - 2020-06-15

Fixed

• The LDJSONVariation, and LDJSONVariationDetail variations now correctly handle empty objects, and arrays.

Added

• A new JSON representation struct LDJSON and a large family of related functions.
• A dedicated C++ wrapper class LDClientCPP
• The LDUserSetCustomAttributesJSON function using struct LDJSON to replace LDUserAddPrivateAttribute
• A LDLogLevel enum for the new logging interface
• A basic logging function that can be used instead of writing your own LDBasicLogger
• The LDConfigureGlobalLogger used for configuring the logging function, and log level
• The LDLogLevelToString function which converts LDLogLevel to a string

Changed

• Instead of make we now use CMake to build the SDK.
• The main include entrypoint is now launchdarkly/api.h instead of ldapi.h
• Previously the SDK defined either a class or struct depending on the language detected. Now there is a dedicated base C interface, and C++ wrapper.
• The types LDClient, LDConfig, and LDUser no longer use a typedef, and require the struct prefix.
• The stdbool.h header have been removed from the public API. All instances of bool have been replaced with LDBoolean which will contain a value of 0 or 1.
• Updated the LDUserSetPrivateAttributes function to accept struct LDJSON
• Updated the LDAllFlags function to return struct LDJSON
• Updated the LDJSONVariation, and LDJSONVariationDetail variations to use struct LDJSON
• The entire public API now has a "defensive mode" enabled by default, which is controlled by the LAUNCHDARKLY_DEFENSIVE compile time definition. This mode will check, and log detectable errors of API usage.
• Internal asserts can be controlled with the LAUNCHDARKLY_USE_ASSERT compile time definition.

Removed

• All old types and functions related to logging
• The LDNode* family of functions
• The LDNode struct
• The LDConfigAddPrivateAttributefunction
• The LDUserSetCustomAttributesJSON function
• The LDUserAddPrivateAttribute function
• The LDClientGetLockedFlags function
• The LDClientUnlockFlags function
• The LD_store_* family of functions

[1.7.6] - 2020-04-01

Fixed:

• Standardized streaming retry behavior. Previously exponential back-off was skipped.

[1.7.5] - 2020-01-17

Fixed:

• The SDK now specifies a uniquely identifiable request header when sending events to LaunchDarkly to ensure that events are only processed once, even if the SDK sends them two times due to a failed initial attempt.

[1.7.4] - 2019-12-17

Changed:

• Artifacts are now released as zip / tar files containing both binaries and headers. No SDK code changes associated with this version bump.

[1.7.3] - 2019-12-16

Fixed:

• Stopped using clock_gettime on OSX which is not supported for older OS versions.

[1.7.2] - 2019-12-16

Fixed:

• Updated cJSON dependency to 1.7.12 (to resolve several known security vulnerabilities)

[1.7.1] - 2019-10-25

Fixed

• Several race conditions in background threads causing lag when closing the client
• Increased validation of HTTP responses
• Simplified internal thread tracking logic
• Increased test coverage and documentation of variation methods

[1.7.0] - 2019-09-26

Added

• Added LDClientTrackMetric which is an extended version of LDClientTrackData but with an extra associated metric value.

[1.6.0] - 2019-09-11

Added

• Added the LDConfigSetSSLCertificateAuthority function. This can be used to specify an alternative certificate authority (such as your own private authority). (Thanks, Aditya Kulkarni!)

[1.5.0] - 2019-07-26

Added

• Added the LDUserFree function. This can be used to free a user object before it has been passed to the client

Fixed

• A leak of HTTP headers set for requests to LaunchDarkly
• A leak of the in memory flag store when LDClientIdentify is called. This was introduced in 1.2.0
• A leak of a structure when events are flushed but no events need to be sent

[1.4.0] - 2019-07-03

Added

• Added the LDConfigSetVerifyPeer configuration option. This option allows disabling certificate verification, which may be useful for testing, or in unfortunate networking configurations. Note that certificate verification should not be disabled unless it is essential, as it makes the SDK vulnerable to man-in-the-middle attacks. (Thanks, mstrater!)

[1.3.2] - 2019-06-20

Fixed

• Fixed a bug where reconnecting in streaming mode sometimes erroneously waited for a timeout when switching users

[1.3.1] - 2019-05-10

Changed:

• Renamed the build artifacts. They are now prefixed with ldclientapi.
• Changed repository references to use the new URL.

There are no other changes in this release. Substituting the build artifacts from version 1.3.0 with the build artifacts from version 1.3.1 will not affect functionality.

Note on future releases

The LaunchDarkly SDK repositories are being renamed for consistency. This repository is now c-client-sdk rather than c-client. (Note that c-server-sdk also exists, which is the server-side C/C++ SDK.)

The library name will also change. In the 1.3.0 release, it is still ldapi; in all future releases, it will be ldclientapi.

[1.3.0] - 2019-04-18

Added:

• Version string macro LD_SDK_VERSION in ldapi.h

[1.2.2] - 2019-04-16

Fixed:

• Ensure LDSetLogFunction is properly exported in shared libraries

[1.2.1] - 2019-04-12

Fixed:

• Cleaned up exported symbols in shared libraries

[1.2.0] - 2019-04-11

Added:

• Added multiple environments support. It is now possible to evaluate flags in additional environments. You can add multiple secondary environments with LDConfigAddSecondaryMobileKey, and use an environment with LDClientGetForMobileKey.
• Added LDNodeAppendHash, and LDNodeAppendArray
• Exposed LDConfigFree (not needed in standard usage)

Fixed:

• Switched to bitflag comparison routines as per cJSON doc
• Memory leak of background thread stack

[1.1.1] - 2019-03-05

Added:

• Improved Windows build documentation
• Added logging on authorization failure

Fixed:

• Fixed a deadlock manifesting on Windows systems

[1.1.0] - 2019-02-01

Added:

• It is now possible to obtain information about how each feature flag value was determined (did the user match a target list or a rule, was the flag turned off, etc.). To do this, add LDConfigSetUseEvaluationReasons(config, true) to your configuration, and then call LD____VariationDetail instea of LD____Variation when evaluating a flag. The "Detail" functions will fill in an LDVariationDetails struct whose reason field is a JSON data structure. See DOCS.md and the SDK reference guide on "Evaluation reasons".

[1.0.0] - 2019-01-10

Initial release.