CHANGELOG.md

Change log

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

[2.9.0] - 2023-01-27

Changed:

• Changed the internal abstractions used for feature stores and updated the implementations to improve performance and reduce memory usage.

Fixed:

• Fixed an issue preventing the proper generation of debug events.

[2.8.7] - 2022-10-25

Changed:

• Testing: refactored cmake project tests to remove unnecessary boilerplate.
• Bumped c-sdk-common dependency, introducing experimental APIs. Such APIs are subject to change or removal, and carry no guarantees.

[2.8.6] - 2022-10-12

Fixed:

• Fixed flag evaluation to report error when flag data is malformed (variation out of bounds).
• Fixed use-after-free in situation where a prerequisite flag has a NULL off-variation.
• Fixed LDAllFlagsState handling of malformed flags, and fixed JSON serialization to omit details properly.

[2.8.5] - 2022-09-01

Fixed:

• Fixed support for CMake versions 3.11 through 3.13, which require an explicit LIBRARY DESTINATION path when installing the SDK's target.

[2.8.4] - 2022-09-01

Fixed:

• Fixed ldserverapi shared library symbol visibility: undocumented symbols previously exposed by 3rd party dependencies are now hidden.

[2.8.3] - 2022-08-09

Fixed:

• Fixed an issue where the SDK was erroneously logging errors when evaluating flags which have an offVariation of null or when the offVariation was not specified.

[2.8.2] - 2022-08-04

Fixed:

• Fixed bug in cmake configuration causing build failures on some platforms due to omission of position-independent code flag.

[2.8.1] - 2022-07-28

Fixed:

• Fixed build error on platforms where char is unsigned by default.

[2.8.0] - 2022-07-12

Added:

• Added CMake minimum version table to README.
• Added 3rd-party dependency table to README.

Changed:

• Updated CMake project configuration to support find_package.
• After installation, it should now be possible to call find_package(ldserverapi [version] REQUIRED) followed by target_link_libraries(app ldserverapi::ldserverapi).
• Note: find_package support does not extend to the Redis integration at this time.
• Please see the README for updated instructions.

[2.7.2] - 2022-07-07

Added:

• Added cmake PROJECT_VERSION variable which reflects the SDK's version.

Fixed:

• Fixed behavior of patch event handling to properly ignore unrecognized paths.

[2.7.1] - 2022-06-24

Fixed:

• Fixed generation of ldserverapi static library release artifacts, which would cause undefined symbol errors during linking.

[2.7.0] - 2022-06-02

Added:

• Added section to README.md with basic CMake integration instructions.

Changed:

• The SDK previously vendored & patched a set of 3rd-party dependencies. These dependencies are now obtained via CMake's FetchContent API, similar to googletest. This required a CMake version bump from 3.10 to 3.11.

Removed:

• Removed most 3rd-party dependencies in third-party subdirectory.
• Removed unused base64 dependency.

[2.6.2] - 2022-05-26

Fixed:

• Null user attributes should never result in a rule match.
• debugEventsUntilDate property of flags obtained via LDAllFlagsState API no longer overflows due to millisecond-precision timestamping.

[2.6.1] - 2022-05-06

Changed:

• Updated language in changelog related to Relay Proxy.
• Updated c-sdk-common dependency.

Fixed:

• Users with empty keys should not generate identify events.
• Removed redundant index event that was generated after an identify event.
• Fixed handling of per-user private attributes in SDK contract tests.

[2.6.0] - 2022-04-20

Added:

• Added integrations/test_data.h. Test Data is a new way to inject feature flag data programmatically into the SDK for testing — either with fixed values for each flag, or with targets and/or rules that can return different values for different users.

• Added integrations/file_data.h. File Data is a new way to inject feature flag data via an external resource.

Fixed:

• Fixed bug in LDAllFlagsState where invalid flags were included in the output.
• Fixed LDConfigSetSendEvents to properly disable analytic events when set to false. As part of this change, public functions LDClientTrack, LDClientTrackMetric, LDClientAlias, and LDClientIdentify now return true when analytic events are disabled.
• Fixed JSON serialization of time values to remove fractional millisecond component.

[2.5.0] - 2022-02-23

Added:

• Added LDVersion(), equivalent to LD_SDK_VERSION. Useful when wrapping the SDK with a higher level language that cannot access the LD_SDK_VERSION symbol.
• Added LDAllFlagsState API for fetching flag values and details. This API is commonly used to bootstrap the client-side Javascript SDK.

Deprecated:

• Deprecated LDAllFlags in favor of LDAllFlagsState. Please invoke LDAllFlagsState() followed by LDAllFlagsStateToValuesMap() for equivalent behavior.

Changed:

• Changed CircleCI macOS executors to Gen2 resource class.
• Swapped CircleCI helgrind test for drd because of false positives within curl dependency.

Fixed

• Fixed LDJSONVariation to allow for returning a flag of any JSON-representable type (previously would return an error if the expected flag type was not object or array.)
• Fixed all LDVariation variants to return hasVariation = false within LDDetails when caller requests wrong flag type.
• Fixed handling of base/stream URIs set by LDConfigSet[Base/Stream]URI with an unintentional trailing slash.
• Fixed double-free bug within LDStoreInitialized.

[2.4.5] - 2022-01-20

Changed:

• Updated CI with dedicated valgrind & helgrind jobs
• Added internal-only JSON helpers.

Fixed:

• Various grammar & spelling issues

[2.4.4] - 2021-12-14

Changed:

• Removed unused internal headers
• Fixed comment spelling issues
• Updated spelling in an error log message (checkPrequisites failed -> checkPrerequisites failed)

Fixed:

• Fixed Windows CI build by updating PCRE download URL to new host

[2.4.3] - 2021-10-19

Changed:

• Updated the build process to produce release artifacts for Windows.
• Updated unit tests to use GoogleTest.

[2.4.2] - 2021-09-17

Fixed:

• In cases where there was a malformed feature flag LDAllFlags would return null instead of all of the valid flags.
• When a malformed feature flag was evaluated events would not be generated for that flag.

[2.4.1] - 2021-07-21

Fixed:

• Refactored parsing logic to provide better error messages and be more reliable.

[2.4.0] - 2021-06-20

Added:

• The SDK now supports the ability to control the proportion of traffic allocation to an experiment. This works in conjunction with a new platform feature now available to early access customers.

[2.3.4] - 2021-06-14

Fixed:

• Removed stray imports of stdbool.h

[2.3.3] - 2021-06-09

Fixed:

• Removed stray imports of stdbool.h

[2.3.2] - 2021-05-26

Fixed:

• Corrected rollout bucketing behavior when bucketing by a user attribute that does not exist.
• Fixed handling of flag rollout bucketing by a specific user attribute.

[2.3.1] - 2021-05-12

Changed:

• Now building with -Werror on Linux and macOS
• Refactored to reduce code duplication between c-client and c-server
• Improved c89 compatibility
• Added clang-format

Fixed:

• A race condition inside the in memory cache when utilizing an external data store. Thanks @lcapaldo
• An instance of using the incorrect enum LD_ERROR instead of LD_LOG_ERROR with LD_LOG
• Resolved many build warnings (that do not impact semantics)

[2.3.0] - 2021-01-28

Added:

• Added the LDClientAlias function. This can be used to associate two user objects for analytics purposes with an alias event.

[2.2.1] - 2021-01-14

Added:

• Vendored Findhiredis to ease building the Redis integration
• Added code coverage reporting functionality to CMake
• Increased unit test coverage

Fixed:

• Added ability to target secondary key
• Internal assertions that should of been API assertions
• A memory leak related to every delivery
• Empty summary events being sent when other events were also being sent
• A leak of custom attributes if the attributes were replaced after already being set
• Fixed inverted defensive check in LDClientIsOffline
• Fixed stream read timeout handling

[2.2.0] - 2020-11-24

Added:

• LDBasicLoggerThreadSafeInitialize used to setup LDBasicLoggerThreadSafe
• LDBasicLoggerThreadSafe a thread safe alternative to LDBasicLogger
• LDBasicLoggerThreadSafeShutdown to cleanup LDBasicLoggerThreadSafe resources

Changed:

• OSX artifacts are now generated with Xcode 9.4.1

Fixed:

• All helgrind concurrency warnings

Deprecated:

• Marked LDBasicLogger as deprecated

[2.1.4] - 2020-07-01

Fixed:

• Added extra public headers to the ldserversdk target to fix Redis usage when embedding the cmake project
• Fixed generation of full fidelity evaluation events for the LaunchDarkly experimentation feature

[2.1.3] - 2020-06-25

Changed:

• Set the "Accept" header to "text/event-stream" for streaming connections.

[2.1.2] - 2020-06-19

Fixed:

• usleep(3) setting errno to EINTR is no longer considered a fatal error.

[2.1.1] - 2020-06-18

Fixed:

• Cap usage of usleep(3) at 999999 usec which is required on certain platforms
• When an error occurs with usleep(3) print errno and not the status code

[2.1.0] - 2020-05-12

Added:

• LDConfigSetWrapperInfo which is used to inform the LaunchDarkly backend of an SDK wrappers name and version. Currently used in our Lua server-side SDK.

[2.0.0] - 2020-04-30

Version 2.0.0 brings many changes, however they are primarily focused on edge cases and internal details. For most customers, this release will be a drop-in replacement and will not require any changes in your SDK usage. When using the SDK, you should either install the SDK configured for your desired location with cmake --build . --target install or use it as a CMake sub-project with the ldserverapi target. The internal organization of files is not part of the API and may change in future releases.

Added:

• Added the capability to remove all assertions at compile time. This is controlled with the compile time definition LAUNCHDARKLY_USE_ASSERT.

Fixed:

• Fixed handling of large time values to fix overflow issues on certain systems: For example 32 bit builds and Windows.
• Waiting until timeout on streaming mode initialization.
• Made CMake more hygienic with target based compilation options.
• Fixed many miscellaneous warnings. Now the SDK is much closer to ANSI compatibility.
• Disabled certain unneeded warnings on Windows.

Changed:

• By default all API operations now use defensive checks instead of assertions by default. This can be controlled based on preference with the compile time definition LAUNCHDARKLY_DEFENSIVE.
• The LDStringVariation and LDJSONVariation functions now accept NULL as fallback values.
• Binary releases are now archives which contain both the headers, and binary, for each platform. These can be extracted and used directly.
• All bool values in the public API now use LDBoolean. This value is a number containing either zero or one. It is currently a char, however this should be considered an opaque detail. This is part of ANSI C compatibility progress.
• Switched to usage of PTHREAD_MUTEX_ERRORCHECK on POSIX. This is controlled with the compile time definition LAUNCHDARKLY_CONCURRENCY_UNSAFE.
• Optimized internals to reduce locking, and switch certain reader/writer locks to mutexes, based on usage pattern.
• Detangled headers reducing complexity.
• Added a mock HTTP server used for integration testing.
• Added stricter compilation options than the exiting -Wextra.
• Greatly simplified internal event generation logic.
• Increased error checking around many system operations.

[1.2.1] - 2020-03-31

Fixed:

• Standardized polling retry behavior. It now simply waits until the next poll interval.
• Standardized event delivery retry behavior. It now retries delivery after one second, a single time.
• Standardized streaming retry behavior. It now correctly follows exponential back-off, changed how status codes are interpreted, and resets back-off after 60 seconds of being successfully connected.

[1.2.0] - 2020-01-22

Added:

• Added support for utilizing external feature stores. See the new launchdarkly/store.h file for details on implementing a store. You can configure usage of a specific store with LDConfigSetFeatureStoreBackend.
• Added support for Redis as an external feature store. To build add -D REDIS_STORE=ON to your cmake build. This will require the hiredis library to be installed on your system.
• Added LaunchDarkly daemon mode configurable with LDConfigSetUseLDD for use with the Relay Proxy. To learn more, read Using daemon mode.
• Added a code coverage reporting system. To build with code coverage add -D COVERAGE=ON to your cmake build. Run the tests, then build the coverage target. This will generate an HTML report.

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.
• Change how time is handled on OSX to support old OSX versions.

[1.1.0] - 2019-09-26

Added

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

Fixed

• Corrected LDReasonToJSON encoding of the RULE_MATCH case.

[1.0.2] - 2019-07-26

Fixed

• Undefined behavior associated with branching on an uninitialized variable when parsing server time headers

[1.0.1] - 2019-07-11

Fixed

• Updated CMAKE header search to include /usr/local/include for OSX Mojave

[1.0.0] - 2019-07-05

Added

• LRU caching to prevent users being indexed multiple times

Fixed

• The server HTTP response time parsing logic

[1.0.0-beta.4] - 2019-06-11

Fixed

• Memory leak when evaluating flags with prerequisites

[1.0.0-beta.3] - 2019-05-17

Added

• Completed Doxygen coverage

Changed

• The header files have been reorganized. Now include "launchdarkly/api.h".

[1.0.0-beta.2] - 2019-04-05

Added

• Windows support
• Networking retry timing jitter
• Analytics debugEventsUntilDate support

[1.0.0-beta.1] - 2019-03-27

Added

• Initial public API
• OSX / Linux builds

Missing

• Windows support
• Networking retry timing jitter
• Analytics debugEventsUntilDate support