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1 Commits
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Author SHA1 Message Date
Jonathan Bernard
3e7f3d4c1e Add version to nimble. 2025-07-07 21:49:35 -05:00
5 changed files with 438 additions and 907 deletions
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1
.gitignore vendored
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@ -3,4 +3,3 @@ nimcache/
tests/tests
src/namespaced_logging.out
src/namespaced_logging/autoconfigured
.worktrees

502
README.md
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@ -1,79 +1,36 @@
# Namespaced Logging for Nim
`namespaced_logging` is intended to be a high-performance, thread-safe logging
framework similar to [std/logging][std-logging] with support for
namespace-scoped logging similar to [log4j][] or [logback][] for Nim. It has
four main motivating features:
`namespaced_logging` provides a logging framework similar to [log4j][] or
[logback][] for Nim. It has three main motivating features:
- Hierarchical, namespaced logging
- Safe and straightforward to use in multi-threaded applications.
- Native support for structured logging.
- Simple, autoconfigured usage pattern reminiscent of the
[std/logging][std-logging] interface (*not yet implemented*)
- Native support for structured logging (old-style string logging is also
supported).
## Getting Started
Install the package via nimble:
Install the package from nimble:
```bash
# Not yet in official Nim packages. TODO once we've battle-tested it a little
nimble install https://github.com/jdbernard/nim-namespaced-logging
nimble install namespaced_logging
```
## Usage Patterns
Then, in your application, you can use the logging system like so:
### Manual Configuration
```nim
import namespaced_logging
# Manually creating a LogService. This is an independent logging root fully
# isolated from subsequent LogServices initialized with initLogService
var ls = initLogService()
# On the main thread
let logService = initLogService()
logService.addAppender(initConsoleAppender(LogLevel.INFO))
# Configure logging
ls.addAppender(initConsoleLogAppender())
ls.addAppender(initFileLogAppender("app.log"))
ls.setThreshold("api", lvlWarn)
# On any thread, including the main thread
let logger = logService.getLogger("app/service/example")
logger.info("Log from the example service")
# Create loggers
let localLogSvc = threadLocalRef(ls)
let apiLogger = localLogSvc.getLogger("api")
let dbLogger = localLogSvc.getLogger("db")
```
### Manual Multithreaded Application
```nim
import namespaced_logging
# Main thread setup
var logService = initLogService()
logService.addAppender(initConsoleLogAppender())
var localLogSvc = threadLocalRef(logService) # for use on main thread
# Worker thread function
proc worker(ls: LogService) {.thread.} =
let localLogSvc = threadLocalRef(ls)
let logger = localLogSvc.getLogger("worker")
# Runtime configuration changes
localLogSvc.setThreshold("worker", lvlDebug)
logger.debug("Worker configured")
# Safe thread creation
createThread(workerThread, worker, logService)
```
### Dynamic Configuration
```nim
# Configuration can change at runtime
proc configureLogging(localLogSvc: ThreadLocalLogService, verbose: bool) =
if verbose:
localLogSvc.setRootThreshold(lvlDebug)
localLogSvc.addAppender(initFileLogAppender("debug.log"))
else:
localLogSvc.setRootThreshold(lvlInfo)
# Changes automatically propagate to all threads
# Only get logs at the WARN or higher level from the database module
let logger = logService.getLogger("app/database", threshold = some(Level.lvlWarn))
logger.error("Database connection failed")
```
## Loggers and Appenders
@ -86,383 +43,140 @@ threshold, which determines which log events are acted upon by the appender,
and, optionally, a namespace filter, which determines from which loggers the
appender accepts log events.
### Heirarchical Logging Namespaces
### Heirarchical Logging and Namespaces
Loggers are organized hierarchically, with the hierarchy defined by the logger
scope. A logger with the scope `app/service/example` is conceptually a child of
the logger with the scope `app/service`. By default, appenders accept log
events from all loggers, but this can be restricted by setting a namespace
filter on the appender. An appender with a namespace set will accept log events
from all loggers with scopes that start with the namespace. For example, an
appender with the namespace `app` will accept log events from the loggers
`app`, `app/service`, and `app/service/example`, but not from `api/service`.
name. A logger with the name `app/service/example` is a child of the logger
with the name `app/service`. By default, appenders accept log events from all
loggers, but this can be restricted by setting a namespace filter on the
appender. An appender with a namespace set will accept log events from all
loggers with names that start with the namespace. For example, an appender with
the namespace `app` will accept log events from the loggers `app`,
`app/service`, and `app/service/example`, but not from `api/service`.
The other impact of the logger heirarchy is in the effective logging level of
the logger. An explicit logging level threshold can be set for any scope. Any
scope that does not have an explicit inherits its threshold from ancestor
loggers upwards in the scope naming heirarchy. This pattern is explained in
detail in the [logback documentation][effective logging level] and applies in
the same manner to loggers in this library.
### LogMessageFormater
Both the [ConsoleLogAppender](#ConsoleLogAppender) and
[FileLogAppender](#FileLogAppender) can be given a *LogMessageFormatter* to
determine how a log message is formatted before being written.
```nim
type LogMessageFormatter* = proc (msg: LogMessage): string {.gcsafe.}
```
## Available Appenders
### ConsoleLogAppender
Used for writing logs to stdout or stderr.
```nim
proc initConsoleLogAppender*(
formatter = formatSimpleTextLog,
## formatJsonStructuredLog is another useful formatter provided
## or you can write your own
useStderr = false, ## stdout is used by default
namespace = "", ## appender matches all scopes by default
threshold = lvlAll ## and accepts all message levels by default
): ConsoleLogAppender {.gcsafe.}
```
The first time a message is sent to any *ConsoleLogAppender*, we create a
writer thread which writes messages to the specified output in the order they
are received, flushing the file handle after each write to enforce an ordering.
The ConsoleLogAppender implementation uses a channel to send messages to the
writer thread.
### FileLogAppender
Used for writing logs to files.
```nim
proc initFileLogAppender*(
filePath: string,
formatter = formatSimpleTextLog,
## formatJsonStructuredLog is another useful formatter provided
## or you can write your own
namespace = "",
threshold = lvlAll
): FileLogAppender {.gcsafe.}
```
Similar to the *ConsoleLogAppender* implementation, the first time a message is
sent to any *FileLogAppender* we create a writer thread which writes messages
to files associated with the *FileLogAppender* configured for the current
*LogService*.
`namespaced_logging` does not currently have built-in logic for file
rotation, but it does play nice with external file rotation strategies. We do
not hold open file handles. The *FileLogAppender* attempts to batch messages
by destination file, opens the file with mode `fmAppend`, writes the current
batch of log messages, and then closes the file handle. Because of this, it has
no problem if another process moves or truncates any of the target log files.
### StdLoggingAppender
Provides a fallback to [std/logging][std-logging]-based logging. This is
primarily intended for use in libraries or other contexts where you want to
fall back to std/logging if the application is not using or hasn't configured
namespaced\_logging.
By default the *StdLoggingAppender* only logs when no namespaced\_logging
appenders are configured but it can also be configured to always forward log
messages regardless of whether namespaced\_logging has other appenders by
setting `fallbackOnly = false`.
```nim
func initStdLoggingAppender*(
fallbackOnly = true,
formatter = formatForwardedLog,
namespace = "",
threshold = lvlAll): StdLoggingAppender {.gcsafe.}
```
### CustomLogAppender
Provides an extension point for custom logging implementations.
```nim
func initCustomLogAppender*[T](
state: T, # arbitrary state needed for the appender
doLogMessage: CustomLogAppenderFunc[T],
# custom log appender implementation
namespace = "",
threshold = lvlAll): CustomLogAppender[T] {.gcsafe.} =
```
The `state` field allows you to explicitly pass in any data that is required
for the custom functionality.
*TODO: rethink this. I chose this to avoid GC-safety issues copying closures
across threads, but maybe I don't need this separate, explicit state field.*
> [!CAUTION] The `state` data type must support copy semantics on assignment.
> It is possible to pass a `ref` to `state` and/or data structures that include
> `ref`s, but **you must guarantee they remain valid**, either by allocating
> shared memeory, or (preferably) keeping alive a reference to them that the GC
> is aware of, either on the thread where they were initialized or by
> explicitly telling the GC about the cross-thread reference *(TODO: how?)*.
See [testutil][] and the unit tests in [namespaced\_logging][nsl-unit-tests]
for an example.
the logger. Any logger can have an explicit logging level set, but if it does
not, the effective logging level is inherited from ancestor loggers upwards in
the logger heirarchy. This pattern is explained in detail in the [logback
documentation][effective logging level] and applies in the same manner to
loggers in this library.
## Notes on Use in Multi-Threaded Applications
The loggers and appenders in this library are thread-safe and are intended to
behave more intuitively in a multi-threaded environment than
[std/logging][std-logging] while presenting a similar API. This is particularly
true in environments where the logging setup code may be separated from the
The loggers and appenders in this library are thread-safe and behaves more
intuitively in a multi-threaded environment than `std/logging`, particularly in
environments where the logging setup code may be separated from the
thread-management code (in an HTTP server, for example).
The *LogService* object is the main entry point for the logging system and
should be initialized on the main thread. The *LogService* contains a reference
to the "source of truth" for logging configuration and is safe to be shared
between all threads.
should be initialized on the main thread. The *LogService* contains the "source
of truth" for logging configuration and is shared between all threads.
Internally all access to the *LogService* is protected by a mutex.
The thread which initializes a *LogService* must also be the longest-living
thread that uses that *LogService* instance. If the initializing thread
terminates or the *LogService* object in that thread goes out of scope while
other threads are still running and using the *LogService*, the global state
may be harvested by the garbage collector, leading to use-after-free errors
when other threads attempt to log (likely causing segfaults).
Logging can be very noisy and if the *LogService* needed to be consulted for
every log event, it could easily become a performance bottleneck. To avoid
this, the *getLogger* procedure makes a thread-local copy of the logging system
configuration (loggers defined and appenders attached).
Individual threads should use the *threadLocalRef* proc to obtain a
*ThreadLocalLogService* reference that can be used to create *Logger* objects.
*ThreadLocalLogService* objects cache the global *LogService* state locally to
avoid expensive locks on the shared state. Instead an atomic configuration
version number is maintained to allow the thread-local state to detect global
configuration changes via an inexpensive [load][atomic-load] call and
automatically synchronize only when necessary.
**Note** that this means that the thread-local cache of the logging system
configuration can become stale if the logging system configuration is changed
after the thread-local copy is made (if another appender is added, for
example). This is a trade-off to avoid the performance penalty of consulting
the *LogService* for every log event.
This thread-local caching mechanism is the primary advantage of this logging
system over std/logging in a multi-threaded environment as it means that
system over `std/logging` in a multi-threaded environment as it means that
the logging system itself is responsible for making sure appenders are
configured for every thread where loggers are used, even if the thread
initialization context is separated from the logging setup code.
If you find yourself needing to change the logging configuration after the
logging system has been initialized, the *reloadThreadState* procedure can be
used to update the thread-local cache of the logging system configuration, but
it must be called on the thread you wish to update.
## Architectural Design
As a final note, the advice to initialize the *LogService* on the main thread
is primarily to simplify the configuration of the logging service and avoid the
need to manually reload caches on individual threads. A *LogService* reference
is required to call *getLogger*, but it can be created on any thread.
### Overview
## Custom Appender Implementations
The namespaced logging library attempts to balance performance, safety, and
usability in multithreaded environments. The design centers on two key types:
*LogService* and *ThreadLocalLogService*.
Due to the thread-safety of the logging system, there are a few additional
considerations when implementing custom appenders. The *LogAppender* abstract
class is the base class for all appenders. To implement a custom appender, two
methods must be implemented:
#### LogService (Value Type)
```nim
type LogService* = object
configVersion: int
global: GlobalLogService
appenders: seq[LogAppender]
thresholds: TableRef[string, Level]
```
The *LogService* object is intended to support uses cases such as:
- **Main thread initialization**: a mutable *LogService* supports all of the
configuration functions you would typically need when initializing logging
for an application on the main thread.
- **Cross-thread communication**: Being an `object` type, *LogService* follows
value semantics and can be safely copied between threads.
- **Service composition**: independently initialized *LogService* objects are
truly independent and multiple can be created and embedded in larger
application contexts.
> [!TIP]
> The *LogService* object is the object that is intended to be shared across
> threads.
#### ThreadLocalLogService (Reference Type)
```nim
type ThreadLocalLogService* = ref LogService
```
*ThreadLocalLogService* is a reference to a thread-local copy of a *LogService*
and can be obtained via *threadLocalRef*. We purposefully use reference
semantics within the context of a thread so that *Logger* objects created
within the same thread context share the same *ThreadLocalLogService*
reference, avoiding the need to synchronize every *Logger* individually.
*ThreadLocalLogService* is the object that users are expected to interact with
during regular operation and support both the configuration functions of
*LogService* and the creation of *Logger* objects.
> [!CAUTION]
> *ThreadLocalLogService* objects should **never** be shared outside the
> context of the thread in which they were initialized.
#### GlobalLogService (Internal)
Under the hood *LogService* holds a reference to a *GlobalLogService*, a
heap-allocated object that serves as the single source of truth for logging
configuration. This internal type is not exposed to library users but manages:
- **Shared configuration state**: Appenders, thresholds, and root logging level
- **Synchronization primitives**: Locks and atomic variables for thread
coordination
- **Background I/O threads**: Dedicated writer threads for console and file
output
- **Configuration versioning**: Atomic version numbers for efficient change
detection
The `GlobalLogService` ensures that configuration changes are safely propagated
across all threads while maintaining high performance for logging operations.
### Thread Safety Model
#### Safe Cross-Thread Pattern
```nim
# Main thread setup
let logService = initLogService()
logService.addAppender(initConsoleLogAppender())
# Safe: value semantics allow crossing thread boundaries
proc workerThread(ls: LogService) {.thread.} =
# Convert to thread-local reference for efficient operations
let tlls = threadLocalRef(ls)
let logger = tlls.getLogger("worker")
logger.info("Worker thread started")
createThread(worker, workerThread, logService)
```
#### Unsafe Pattern (Avoided by Design)
```nim
# DON'T DO THIS - unsafe reference sharing
# ThreadLocalLogService should not be shared across threads
let tlls = threadLocalRef(initLogService())
createThread(worker, someProc, tlls) # ❌ Potential GC issues
```
### Configuration Synchronization
#### Atomic Version Checking
The library uses atomic version numbers to efficiently detect configuration
changes:
### `appendLogMessage`
```nim
proc ensureFreshness*(ls: var LogService) =
# Cheap atomic check first
if ls.configVersion == ls.global.configVersion.load():
return # No changes, return immediately
# Only acquire lock and copy if versions differ
withLock ls.global.lock:
ls.configVersion = ls.global.configVersion.load
# Sync state...
method appendLogMessage*(appender: CustomLogAppender, msg: LogMessage): void {.base, gcsafe.}
```
Goals/Motivation:
- Most logging operations skip expensive synchronization so the hot path is
fast.
- Propogate changes automatically so all threads see configuration updates.
- Minimize lock contention by only acquiring when configuration changes
This is the primary appender implementation that takes a LogMessage and
writes it to the appender's destination. As the signature suggests, the
implementation must be GC-safe. As a multi-method, the *CustomLogAppender* type
should be replaced by the actual name of your custom appender.
#### Thread-Local Caching
Because the *LogAppender* uses multi-methods for dynamic dispatch, the
custom appender class must also be a `ref` type.
Each thread maintains its own copy of the logging configuration in
*ThreadLocalLogService*:
- **Appenders**: Thread-local copies created via `clone()` method
- **Thresholds**: Complete copy of namespace-to-level mappings
- **Version tracking**: Local version number for change detection
This caching strategy provides:
- **High performance**: No locks needed for normal logging operations
- **Consistency**: All threads eventually see the same configuration
- **Isolation**: Thread-local state prevents cross-thread interference
## Error Handling
### Overview
For errors that occur during logging operations, there is a callback-based
error handling system designed to attempt to gracefully handle such failures.
Since logging is typically a non-critical operation we prioritize application
stability over guaranteed log delivery.
### Error Handler
The library uses a callback-based error handling pattern where applications can
register custom error handlers to be notified when logging operations fail. The
error handler receives:
- `error`: The exception that caused the failure
- `msg`: A descriptive message providing context about where the error occurred
### `initThreadCopy`
```nim
type ErrorHandlerFunc* = proc(error: ref Exception, msg: string) {.gcsafe, nimcall.}
method initThreadCopy*(app: LogAppender): LogAppender {.base, gcsafe.}
```
### Default Error Handler
This method is used to create a thread-local copy of the appender. It is called
by the *reloadThreadState* procedure to update the thread-local cache of the
logging system configuration. The implementation will be passed the appender
instance that was provided to the *addAppender* procedure and must return a
thread-local copy of that appender.
namespaced\_logging uses the `defaultErrorHandlerFunc` if a custom error
handler has not been configured. The default handler:
The `initThreadCopy` implementations for the built-in *ConsoleLogAppender* and
*FileLogAppender* provide simple examples of how to implement this method by
simply copying state into the local thread, but this method can also be used
to perform any other thread-specific initialization that may be required for
the appender implementation.
1. Attempts to write to stderr, assuming it is likely to be available and monitored
2. Writes an error message and includes both the exception message and stack
trace (not available in release mode).
3. Fails silently if it is unable to write to to stderr.
### Example Custom Appender
### Configuration
#### Setting Custom Error Handlers
```nim
# During initialization
var logService = initLogService(errorHandler = myCustomErrorHandler)
# Or at runtime on either the LogService...
logService.setErrorHandler(myCustomErrorHandler)
# ... or on a ThreadLocalLogService
var localLogSvc = threadLocalRef(logService)
localLogSvc.setErrorHandler(myCustomErrorHandler)
```
#### Disabling Error Reporting
```nim
proc silentErrorHandler(err: ref Exception, msg: string) {.gcsafe, nimcall.} =
discard # Do nothing
logService.setErrorHandler(silentErrorHandler)
```
### Best Practices
#### Provide Fallbacks
The following defines a simple custom appender that writes log messages to a
database table. It uses the [waterpark][] connection pooling library to manage
database connections as waterpark is also thread-safe and makes implementation
straight-forward.
```nim
proc robustErrorHandler(err: ref Exception, msg: string) {.gcsafe, nimcall.} =
# Primary: Send to monitoring system
if not sendToMonitoring(err, msg):
# Secondary: Write to dedicated error log
if not writeToErrorLog(err, msg):
# Tertiary: Use stderr as last resort
try:
stderr.writeLine("LOGGING ERROR [" & msg & "]: " & err.msg)
stderr.flushFile()
except: discard
import db_connectors/db_postgres
import namespaced_logging, waterpark, waterpark/db_postgres
type DbLogAppender = ref object of LogAppender
dbPool: PostgresPool
let dbPool: PostgresPool = newPostgresPool(10, "", "", "", connectionString)
method initThreadCopy*(app: LogAppender): LogAppender =
result = DbLogAppender(dbPool: dbPool) # copy semantics as PostgresPool is an object
method appendLogMessage*(appender: DbLogAppender, msg: LogMessage): void {gcsafe.} =
appender.withConnection conn:
conn.insert(
"INSERT INTO log_events " &
" (level, scope, message, error, timestamp, custom_fields) " &
"VALUES " &
" (?, ?, ?, ?, ?, ?)",
msg.level,
msg.scope,
msg.message,
if msg.error.isSome: msg.error.msg
else: "",
msg.timestamp,
msg.additionalData)
```
#### Keep Error Handlers Simple
As much as possible, avoid complex operations that might themselves fail.
Don't do heavy operations like database writes, complex network operations, or
file system operations that might fail and cause cascading errors.
[log4j]: https://logging.apache.org/log4j/2.x/
[logback]: https://logback.qos.ch/
[effective logging level]: https://logback.qos.ch/manual/architecture.html#effectiveLevel
[atomic-load]: https://nim-lang.org/docs/atomics.html#load%2CAtomic%5BT%5D%2CMemoryOrder
[std-logging]: https://nim-lang.org/docs/logging.html
[testutil]: /blob/main/src/namespaced_logging/testutil.nim
[nsl-unit-tests]: https://github.com/jdbernard/nim-namespaced-logging/blob/main/src/namespaced_logging.nim#L904

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namespaced_logging.nimble
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@ -1,6 +1,6 @@
# Package
version = "2.0.3"
version = "2.0.0"
author = "Jonathan Bernard"
description = "Wrapper around std/logging to provide namespaced logging."
license = "MIT"
@ -13,7 +13,3 @@ requires @["nim >= 2.2.0", "zero_functional"]
# from https://git.jdb-software.com/jdb/nim-packages
requires "timeutils"
task test, "Run unittests for the package.":
exec "nimble c src/namespaced_logging.nim"
exec "src/namespaced_logging.out"

738
src/namespaced_logging.nim
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@ -1,10 +1,9 @@
import std/[algorithm, atomics, exitprocs, json, locks, options, os, paths,
sequtils, strutils, tables, times]
import std/[algorithm, atomics, json, locks, options, os, paths, sequtils,
strutils, tables, times]
import timeutils
import std/logging as stdlog
from std/logging import Level
export Level
from logging import Level
export logging.Level
type
GlobalLogServiceObj {.acyclic.} = object
@ -16,9 +15,13 @@ type
thresholds: TableRef[string, Level]
rootLevel: Atomic[Level]
console: ThreadedConsoleLoggingState
file: ThreadedFileLoggingState
errorHandler: ErrorHandlerFunc
errorHandlerLock: Lock
GlobalLogService = ref GlobalLogServiceObj
@ -38,7 +41,7 @@ type
ThreadLocalLogService* = ref LogService
Logger* = ref object
Logger* = object
scope*: string
threadSvc: ThreadLocalLogService
@ -84,11 +87,18 @@ type
absPath: Path
LogWriterThreadState[M] = object
ThreadedConsoleLoggingState = object
initialized: Atomic[bool]
shutdown: Atomic[bool]
chan: Channel[M]
writerThread: Thread[void]
chan: Channel[ConsoleMessage]
writerThread: Thread[GlobalLogService]
ThreadedFileLoggingState = object
initialized: Atomic[bool]
shutdown: Atomic[bool]
chan: Channel[FileMessage]
writerThread: Thread[GlobalLogService]
ConsoleLogAppender* = ref object of LogAppender
@ -113,61 +123,6 @@ type
formatter*: LogMessageFormatter
absPath*: Path
StdLoggingAppender* = ref object of LogAppender
## Log appender that forwards log messages to the std/logging
## implementation. This is primarily intended for libraries and other
## situations where you expect that your code will be third-party to others
## and want to respect applications which use std/logging for log handlers
## and configuration.
fallbackOnly*: bool
## when true, only forward to std/logging where there are no appenders
## configured on the related LogService
formatter*: LogMessageFormatter
const UninitializedConfigVersion = low(int)
let JNULL = newJNull()
var consoleLogging {.global.}: LogWriterThreadState[ConsoleMessage]
var fileLogging {.global.}: LogWriterThreadState[FileMessage]
var loggingThreadInitLock {.global.}: Lock
initLock(loggingThreadInitLock)
proc initLogMessage*(
scope: string,
lvl: Level,
message: string,
error: Option[ref Exception] = none[ref Exception](),
additionalData: JsonNode = JNULL): LogMessage =
LogMessage(
scope: scope,
level: lvl,
error: error,
timestamp: now(),
message: message,
additionalData: additionalData)
proc initLogMessage*(
scope: string,
lvl: Level,
msg: JsonNode,
error: Option[ref Exception] = none[ref Exception]()): LogMessage =
LogMessage(
scope: scope,
level: lvl,
error: error,
timestamp: now(),
message:
if msg.hasKey("message"): msg["message"].getStr
else: "",
additionalData: msg)
method clone*(app: LogAppender): LogAppender {.base, gcsafe.} =
raise newException(CatchableError, "missing concrete implementation")
@ -189,39 +144,40 @@ proc defaultErrorHandlerFunc*(
stderr.flushFile()
except Exception: discard # we tried...
proc shutdownThreadedConsoleLogging() =
if not consoleLogging.initialized.load(): return
proc shutdownThreadedConsoleLogging(gls: var GlobalLogServiceObj) =
if not gls.console.initialized.load(): return
withLock loggingThreadInitLock:
consoleLogging.shutdown.store(true) # signal shutdown
gls.console.shutdown.store(true) # signal shutdown
# Send sentinel values to wake up the writer thread
try: consoleLogging.chan.send(ConsoleMessage(message: "", useStderr: false))
except Exception: discard
# Send sentinel values to wake up the writer thread
try: gls.console.chan.send(ConsoleMessage(message: "", useStderr: false))
except Exception: discard
joinThread(consoleLogging.writerThread)
consoleLogging.chan.close()
consoleLogging.initialized.store(false)
joinThread(gls.console.writerThread)
gls.console.chan.close()
gls.console.initialized.store(false)
proc shutdownThreadedFileLogging() =
if not fileLogging.initialized.load(): return
proc shutdownThreadedFileLogging(gls: var GlobalLogServiceObj) =
if not gls.file.initialized.load(): return
fileLogging.shutdown.store(true) # signal shutdown
gls.file.shutdown.store(true) # signal shutdown
withLock loggingThreadInitLock:
try: fileLogging.chan.send(FileMessage(message: "", absPath: Path("/")))
except Exception: discard
try: gls.file.chan.send(FileMessage(message: "", absPath: Path("/")))
except Exception: discard
joinThread(fileLogging.writerThread)
fileLogging.chan.close()
fileLogging.initialized.store(false)
joinThread(gls.file.writerThread)
gls.file.chan.close()
gls.file.initialized.store(false)
proc `=destroy`*(gls: var GlobalLogServiceObj) =
# only one thread should cleanup
if not gls.initialized.exchange(false): return
gls.shutdownThreadedConsoleLogging()
gls.shutdownThreadedFileLogging()
try: deinitLock(gls.lock)
except Exception: discard
@ -254,28 +210,6 @@ proc ensureFreshness*(ls: var LogService) =
proc ensureFreshness*(ls: ThreadLocalLogService) = ensureFreshness(ls[])
proc initGlobalLogService(
rootLevel = lvlAll,
errorHandler = defaultErrorHandlerFunc): GlobalLogService =
result = GlobalLogService()
result.configVersion.store(0)
initLock(result.lock)
initLock(result.errorHandlerLock)
result.appenders = @[]
result.thresholds = newTable[string, Level]()
result.rootLevel.store(rootLevel)
result.errorHandler = errorHandler
result.initialized.store(true)
proc initLogService(gls: GlobalLogService): LogService =
var lsRef: ThreadLocalLogService = ThreadLocalLogService(
configVersion: UninitializedConfigVersion, global: gls)
ensureFreshness(lsRef)
result = lsRef[]
proc initLogService*(
rootLevel = lvlAll,
errorHandler = defaultErrorHandlerFunc): LogService =
@ -293,12 +227,24 @@ proc initLogService*(
## configure thresholds, and create loggers. The ref returned by this
## procedure should also be retained by the main thread so that garbage
## collection does not harvest the global state while it is still in use.
let global = initGlobalLogService(rootLevel, errorHandler)
result = initLogService(global)
let global = GlobalLogService()
global.configVersion.store(0)
global.initialized.store(true)
initLock(global.lock)
initLock(global.errorHandlerLock)
global.appenders = @[]
global.thresholds = newTable[string, Level]()
global.rootLevel.store(rootLevel)
global.errorHandler = errorHandler
var lsRef: ThreadLocalLogService = ThreadLocalLogService(configVersion: -1, global: global)
ensureFreshness(lsRef)
result = lsRef[]
proc threadLocalRef*(ls: LogService): ThreadLocalLogService =
new result
result = new(LogService)
result[] = ls
@ -391,17 +337,6 @@ proc setThreshold*(ls: ThreadLocalLogService, scope: string, lvl: Level) {.gcsaf
setThreshold(ls[], scope, lvl)
proc setThresholds*(ls: var LogService, thresholds: TableRef[string, Level]) {.gcsafe.} =
withLock ls.global.lock:
for k,v in thresholds: ls.global.thresholds[k] = v
ls.global.configVersion.atomicInc
ensureFreshness(ls)
proc setThresholds*(ls: ThreadLocalLogService, thresholds: TableRef[string, Level]) {.gcsafe.} =
setThresholds(ls[], thresholds)
proc getLogger*(
ls: ThreadLocalLogService,
scope: string,
@ -427,21 +362,6 @@ proc getLogger*(
result = Logger(scope: scope, threadSvc: ls)
proc getLogger*(
ls: Option[ThreadLocalLogService],
scope: string,
lvl: Option[Level] = none[Level]()): Option[Logger] {.gcsafe.} =
return
if ls.isSome: some(getLogger(ls.get, scope, lvl))
else: none[Logger]()
proc appenders*(ls: var LogService): seq[LogAppender] {.gcsafe.} =
for a in ls.appenders: result.add(clone(a))
proc appenders*(ls: ThreadLocalLogService): seq[LogAppender] {.gcsafe.} =
ls[].appenders()
proc addAppender*(ls: var LogService, appender: LogAppender) {.gcsafe.} =
## Add a log appender to the global log service and refresh the local thread
## state. The updated global state will trigger other threads to refresh
@ -458,19 +378,6 @@ proc addAppender*(ls: ThreadLocalLogService, appender: LogAppender) {.gcsafe.} =
addAppender(ls[], appender)
proc clearAppenders*(ls: var LogService) {.gcsafe.} =
## Remove all log appenders added to the global log service and refresh the
## local thread state. The updated global state will trigger other threads to
## refresh their state as well.
withLock ls.global.lock:
ls.global.appenders = @[]
ls.global.configVersion.atomicInc
proc clearAppenders*(ls: ThreadLocalLogService) {.gcsafe.} =
clearAppenders(ls[])
func getEffectiveThreshold(logger: Logger): Level {.gcsafe.} =
## Get the effective logging level threshold for a logger. This is the most
## specific level that is set for the logger or any of its parents. The root
@ -492,173 +399,89 @@ func getEffectiveThreshold(logger: Logger): Level {.gcsafe.} =
result = logger.threadSvc.thresholds[namespaces[0]]
proc isEnabled*(l: Logger, lvl: Level): bool {.inline,gcsafe.} =
lvl >= l.getEffectiveThreshold
proc doLog(logger: Logger, msg: LogMessage) {.gcsafe.} =
ensureFreshness(logger.threadSvc)
if msg.level < logger.getEffectiveThreshold: return
proc sendToAppenders(logger: Logger, msg: LogMessage) {.gcsafe,inline.} =
for app in logger.threadSvc.appenders:
if logger.scope.startsWith(app.namespace) and msg.level >= app.threshold:
app.appendLogMessage(logger.threadSvc, msg)
template log*(l: Logger, lm: LogMessage) =
ensureFreshness(l.threadSvc)
if lm.level >= l.getEffectiveThreshold:
sendToAppenders(l, lm)
template log*(l: Logger, lvl: Level, msg: untyped) =
ensureFreshness(l.threadSvc)
if lvl >= l.getEffectiveThreshold:
sendToAppenders(l, initLogMessage(l.scope, lvl, msg))
proc log*(l: Logger, lvl: Level, msg: string) {.gcsafe.} =
l.doLog(LogMessage(
scope: l.scope,
level: lvl,
error: none[ref Exception](),
timestamp: now(),
message: msg,
additionalData: newJNull()))
template log*[T: ref Exception](l: Logger, lvl: Level, err: T, msg: untyped) =
ensureFreshness(l.threadSvc)
if lvl >= l.getEffectiveThreshold:
sendToAppenders(
l,
initLogMessage(l.scope, lvl, msg, some(cast[ref Exception](err))))
template log*(l: Option[Logger], lm: LogMessage) =
if l.isSome: log(l.get, lm)
template log*(l: Option[Logger], lvl: Level, msg: untyped) =
if l.isSome: log(l.get, lvl, msg)
template log*(
l: Option[Logger],
proc log*(
l: Logger,
lvl: Level,
error: ref Exception,
msg: untyped) =
msg: string ) {.gcsafe.} =
l.doLog(LogMessage(
scope: l.scope,
level: lvl,
error: some(error),
timestamp: now(),
message: msg,
additionalData: newJNull()))
proc log*(l: Logger, lvl: Level, msg: JsonNode) {.gcsafe.} =
l.doLog(LogMessage(
scope: l.scope,
level: lvl,
error: none[ref Exception](),
timestamp: now(),
message:
if msg.hasKey("msg"): msg["msg"].getStr
else: "",
additionalData: msg))
proc log*(l: Option[Logger], lvl: Level, msg: string) {.gcsafe.} =
if l.isSome: log(l.get, lvl, msg)
proc log*(l: Option[Logger], lvl: Level, msg: JsonNode) {.gcsafe.} =
if l.isSome: log(l.get, lvl, msg)
proc log*(l: Option[Logger], lvl: Level, error: ref Exception, msg: string) {.gcsafe.} =
if l.isSome: log(l.get, lvl, error, msg)
template debug*[L: Logger or Option[Logger], M](l: L, msg: M) =
log(l, lvlDebug, msg)
template debug*[T](l: Logger, msg: T) = log(l, lvlDebug, msg)
template info*[T](l: Logger, msg: T) = log(l, lvlInfo, msg)
template notice*[T](l: Logger, msg: T) = log(l, lvlNotice, msg)
template warn*[T](l: Logger, msg: T) = log(l, lvlWarn, msg)
template info*[L: Logger or Option[Logger], M](l: L, msg: M) =
log(l, lvlInfo, msg)
template notice*[L: Logger or Option[Logger], M](l: L, msg: M) =
log(l, lvlNotice, msg)
template warn*[L: Logger or Option[Logger], M](l: L, msg: M) =
log(l, lvlWarn, msg)
template error*[L: Logger or Option[Logger], M](l: L, msg: M) =
log(l, lvlError, msg)
template error*[L: Logger or Option[Logger], M](l: L, error: ref Exception, msg: M) =
template error*[T](l: Logger, msg: T) = log(l, lvlError, msg)
template error*(l: Logger, error: ref Exception, msg: string) =
log(l, lvlError, error, msg)
template fatal*[L: Logger or Option[Logger], M](l: L, msg: M) =
log(l, lvlFatal, msg)
template fatal*[L: Logger or Option[Logger], M](l: L, error: ref Exception, msg: M) =
template fatal*[T](l: Logger, msg: T) = log(l, lvlFatal, msg)
template fatal*(l: Logger, error: ref Exception, msg: string) =
log(l, lvlFatal, error, msg)
template debug*[T](l: Option[Logger], msg: T) = log(l, lvlDebug, msg)
template info*[T](l: Option[Logger], msg: T) = log(l, lvlInfo, msg)
template notice*[T](l: Option[Logger], msg: T) = log(l, lvlNotice, msg)
template warn*[T](l: Option[Logger], msg: T) = log(l, lvlWarn, msg)
template error*[T](l: Option[Logger], msg: T) = log(l, lvlError, msg)
template error*(l: Option[Logger], error: ref Exception, msg: string) =
log(l, lvlError, error, msg)
template fatal*[T](l: Option[Logger], msg: T) = log(l, lvlFatal, msg)
template fatal*(l: Option[Logger], error: ref Exception, msg: string) =
log(l, lvlFatal, error, msg)
# -----------------------------------------------------------------------------
# Writer Thread Implementations
# -----------------------------------------------------------------------------
proc consoleWriterLoop() {.thread.} =
while not consoleLogging.shutdown.load():
var didSomething = false
let (hasData, msg) = consoleLogging.chan.tryRecv()
if hasData and msg.message.len > 0: # Skip empty sentinel messages
try:
let output =
if msg.useStderr: stderr
else: stdout
output.write(msg.message)
output.flushFile()
didSomething = true
except IOError:
discard
# Small delay if no work to prevent busy waiting
if not didSomething: sleep(100)
proc fileWriterLoop() {.thread.} =
const bufLen = 128
var msgsByPath = newTable[Path, seq[FileMessage]]()
while not fileLogging.shutdown.load():
var didSomething = false
var msgBuf: array[bufLen, FileMessage]
var recvIdx = 0
var writeIdx = 0
var dataAvailable = true
while dataAvailable and recvIdx < bufLen:
# Fill our message buffer if we can
(dataAvailable, msgBuf[recvIdx]) = fileLogging.chan.tryRecv()
if dataAvailable: inc recvIdx
# Organize messages by destination file
msgsByPath.clear()
while writeIdx < recvIdx:
let msg = msgBuf[writeIdx]
inc writeIdx
if msg.message.len > 0: # skip empty sentinel messages
if not msgsByPath.contains(msg.absPath): msgsByPath[msg.absPath] = @[]
msgsByPath[msg.absPath].add(msg)
didSomething = true
# Write all messages in file order to optimize file open/flush/close
for path, msgs in pairs(msgsByPath):
var f: File
if not open(f, $path, fmAppend):
# TODO: can we do better than silently failing here?
continue
for m in msgs:
try: writeLine(f, m.message)
except Exception: discard
flushFile(f)
close(f)
# Wait a bit if we had no work to prevent busy waiting
if not didSomething: sleep(100)
proc initThreadedConsoleLogging() =
if consoleLogging.initialized.load: return
withLock loggingThreadInitLock:
if consoleLogging.initialized.load: return
consoleLogging.chan.open()
consoleLogging.shutdown.store(false)
# Create writer thread with reference to the service
createThread(consoleLogging.writerThread, consoleWriterLoop)
consoleLogging.initialized.store(true)
proc initThreadedFileLogging() =
if fileLogging.initialized.load: return
withLock loggingThreadInitLock:
if fileLogging.initialized.load: return
fileLogging.chan.open()
fileLogging.shutdown.store(false)
# Create writer thread with reference to the service
createThread(fileLogging.writerThread, fileWriterLoop)
fileLogging.initialized.store(true)
# -----------------------------------------------------------------------------
# CustomLogAppender Implementation
# CustomerLogAppender Implementation
# -----------------------------------------------------------------------------
func initCustomLogAppender*[T](
@ -668,7 +491,7 @@ func initCustomLogAppender*[T](
threshold = lvlAll): CustomLogAppender[T] {.gcsafe.} =
if doLogMessage.isNil:
raise newException(ValueError, "initCustomLogAppender: doLogMessage is nil")
debugEcho "initCustomLogAppender: doLogMessage is nil"
result = CustomLogAppender[T](
namespace: namespace,
@ -677,8 +500,8 @@ func initCustomLogAppender*[T](
state: state)
method clone*[T](cla: CustomLogAppender[T]): LogAppender {.gcsafe.} =
assert not cla.doLogMessage.isNil,
"CustomLogAppender#clone: source doLogMessage is nil"
if cla.doLogMessage.isNil:
debugEcho "CustomLogAppender#clone: source doLogMessage is nil"
result = CustomLogAppender[T](
namespace: cla.namespace,
@ -693,7 +516,7 @@ method appendLogMessage[T](
msg: LogMessage) {.gcsafe.} =
try:
if cla.doLogMessage.isNil:
raise newException(ValueError, "CustomLogAppender.appendLogMessage: doLogMessage is nil")
debugEcho "doLogMessage is nil"
else: cla.doLogMessage(cla.state, msg)
except Exception:
ls.global.reportLoggingError(
@ -717,6 +540,41 @@ proc initConsoleLogAppender*(
useStderr: useStderr)
proc consoleWriterLoop(gls: GlobalLogService) {.thread.} =
while not gls.console.shutdown.load():
var didSomething = false
let (hasData, msg) = gls.console.chan.tryRecv()
if hasData and msg.message.len > 0: # Skip empty sentinel messages
try:
let output =
if msg.useStderr: stderr
else: stdout
output.write(msg.message)
output.flushFile()
didSomething = true
except IOError:
discard
# Small delay if no work to prevent busy waiting
if not didSomething: sleep(100)
proc initThreadedConsoleLogging(gls: GlobalLogService) =
if gls.console.initialized.load() or # don't double-init
not gls.initialized.load(): # don't init if the gls is shutting down
return
withLock gls.lock:
if gls.console.initialized.load(): return
gls.console.chan.open()
gls.console.shutdown.store(false)
# Create writer thread with reference to the service
createThread(gls.console.writerThread, consoleWriterLoop, gls)
gls.console.initialized.store(true)
method clone*(cla: ConsoleLogAppender): LogAppender {.gcsafe.} =
result = ConsoleLogAppender(
namespace: cla.namespace,
@ -730,11 +588,11 @@ proc appendLogMessageMultiThreaded(
ls: ref LogService,
msg: LogMessage) {.gcsafe.} =
if not consoleLogging.initialized.load():
initThreadedConsoleLogging()
if not ls.global.console.initialized.load():
ls.global.initThreadedConsoleLogging()
try:
consoleLogging.chan.send(ConsoleMessage(
ls.global.console.chan.send(ConsoleMessage(
message: cla.formatter(msg),
useStderr: cla.useStderr))
except Exception:
@ -801,6 +659,67 @@ proc initFileLogAppender*(
formatter: formatter,
absPath: absolutePath(Path(filePath)))
# TODO: initialize global state for the file log writer
proc fileWriterLoop(gls: GlobalLogService) {.thread.} =
const bufLen = 128
var msgsByPath = newTable[Path, seq[FileMessage]]()
while not gls.file.shutdown.load():
var didSomething = false
var msgBuf: array[bufLen, FileMessage]
var recvIdx = 0
var writeIdx = 0
var dataAvailable = true
while dataAvailable and recvIdx < bufLen:
# Fill our message buffer if we can
(dataAvailable, msgBuf[recvIdx]) = gls.file.chan.tryRecv()
if dataAvailable: inc recvIdx
# Organize messages by destination file
msgsByPath.clear()
while writeIdx < recvIdx:
let msg = msgBuf[writeIdx]
inc writeIdx
if msg.message.len > 0: # skip empty sentinel messages
if not msgsByPath.contains(msg.absPath): msgsByPath[msg.absPath] = @[]
msgsByPath[msg.absPath].add(msg)
didSomething = true
# Write all messages in file order to optimize file open/flush/close
for path, msgs in pairs(msgsByPath):
var f: File
if not open(f, $path, fmAppend):
# TODO: can we do better than silently failing here?
continue
for m in msgs:
try: writeLine(f, m.message)
except Exception: discard
flushFile(f)
close(f)
# Wait a bit if we had no work to prevent busy waiting
if not didSomething: sleep(100)
proc initThreadedFileLogging(gls: GlobalLogService) =
if gls.file.initialized.load(): return
withLock gls.lock:
if gls.file.initialized.load(): return
gls.file.chan.open()
gls.file.shutdown.store(false)
# Create writer thread with reference to the service
createThread(gls.file.writerThread, fileWriterLoop, gls)
gls.file.initialized.store(true)
method clone*(fla: FileLogAppender): LogAppender {.gcsafe.} =
result = FileLogAppender(
@ -815,11 +734,11 @@ proc appendLogMessageMultiThreaded(
ls: ref LogService,
msg: LogMessage) {.gcsafe.} =
if not fileLogging.initialized.load():
initThreadedFileLogging()
if not ls.global.file.initialized.load():
ls.global.initThreadedFileLogging()
try:
fileLogging.chan.send(FileMessage(
ls.global.file.chan.send(FileMessage(
message: fla.formatter(msg),
absPath: fla.absPath))
except Exception: discard
@ -855,66 +774,14 @@ method appendLogMessage(
"unable to append to FileLogAppender")
# -----------------------------------------------------------------------------
# StdLoggingAppender Implementation
# -----------------------------------------------------------------------------
func formatForwardedLog*(lm: LogMessage): string =
## Default formatter for the StdLoggingAppender that prepends the logger
## scope to the message before formatting the message via
## *formatSimpleTextLog*
"[" & lm.scope & "] " & formatSimpleTextLog(lm)
func initStdLoggingAppender*(
fallbackOnly = true,
formatter = formatForwardedLog,
namespace = "",
threshold = lvlAll): StdLoggingAppender {.gcsafe.} =
result = StdLoggingAppender(
namespace: namespace,
threshold: threshold,
fallbackOnly: fallbackOnly,
formatter: formatter)
method clone*(sla: StdLoggingAppender): LogAppender {.gcsafe.} =
result = StdLoggingAppender(
namespace: sla.namespace,
threshold: sla.threshold,
fallbackOnly: sla.fallbackOnly,
formatter: sla.formatter)
method appendLogMessage*(
sla: StdLoggingAppender,
ls: ThreadLocalLogService,
msg: LogMessage) {.gcsafe.} =
if sla.fallbackOnly and ls.appenders.len > 1: return
stdlog.log(msg.level, sla.formatter(msg))
# -----------------------------------------------------------------------------
# Cleanup
# -----------------------------------------------------------------------------
addExitProc(proc() =
shutdownThreadedConsoleLogging()
shutdownThreadedFileLogging()
)
# -----------------------------------------------------------------------------
# Tests
# -----------------------------------------------------------------------------
when isMainModule:
import std/[files, tempfiles, unittest]
import std/[tempfiles, unittest]
import ./namespaced_logging/testutil
# -----------------------------------------------------------------------------
# Tests
# -----------------------------------------------------------------------------
suite "GlobalLogService Initialization":
@ -1038,7 +905,8 @@ when isMainModule:
setup:
let ls = threadLocalRef(initLogService())
let loggedMsgs = initLoggedMessages()
ls.addAppender(initTestLogAppender(loggedMsgs))
let testAppender = initTestLogAppender(loggedMsgs)
ls.addAppender(testAppender)
test "getLogger creates logger with correct scope":
let logger = ls.getLogger("api/users")
@ -1048,26 +916,6 @@ when isMainModule:
let logger = ls.getLogger("api/users", some(lvlWarn))
check ls.thresholds["api/users"] == lvlWarn
test "log methods work":
let logger = ls.getLogger("test")
logger.log(lvlDebug, "debug string msg")
logger.log(lvlInfo, %*{"message": "info json msg"})
logger.log(lvlNotice, "notice string msg")
logger.log(lvlError, newException(ValueError, "exception msg"), "error ex. msg")
let lm = loggedMsgs.get()
check:
lm.len == 4
lm[0].level == lvlDebug
lm[0].message.contains("debug string msg")
lm[1].level == lvlInfo
lm[1].message.contains("info json msg")
lm[2].level == lvlNotice
lm[2].message.contains("notice string msg")
lm[3].level == lvlError
lm[3].message.contains("error ex. msg")
test "logger convenience methods work":
let logger = ls.getLogger("test")
@ -1116,7 +964,8 @@ when isMainModule:
setup:
let ls = threadLocalRef(initLogService())
let loggedMsgs = initLoggedMessages()
ls.addAppender(initTestLogAppender(loggedMsgs))
let testAppender = initTestLogAppender(loggedMsgs)
ls.addAppender(testAppender)
test "root level filtering":
ls.setRootThreshold(lvlInfo)
@ -1166,25 +1015,6 @@ when isMainModule:
lm[0].scope == "api/users/detail"
lm[0].level == lvlDebug
test "message construction is avoided if the message is not logged":
var expensiveCallCount = 0
proc expensiveCall(): int =
inc expensiveCallCount
return expensiveCallCount
ls.setThreshold("test", lvlInfo)
let logger = ls.getLogger("test")
logger.debug("Expensive call (" & $expensiveCall() & ")")
logger.info("Expensive call (" & $expensiveCall() & ")")
let lm = loggedMsgs.get()
check:
lm.len == 1
lm[0].message.contains("Expensive call (1)")
expensiveCallCount == 1
suite "Appender Functionality":
setup:
let ls = threadLocalRef(initLogService())
@ -1283,8 +1113,6 @@ when isMainModule:
lines.len == 1
"test message" in lines[0]
removeFile(pathStr)
test "file appender clone":
let original = initFileLogAppender("tempfile.log", namespace = "test")
let cloned = clone(original)
@ -1293,107 +1121,3 @@ when isMainModule:
let clonedFile = FileLogAppender(cloned)
check clonedFile.absPath == original.absPath
check clonedFile.namespace == "test"
suite "StdLoggingAppender":
var fileLogger: FileLogger
var tempFile: File
var tempFilename: string
setup:
let ls = threadLocalRef(initLogService())
(tempFile, tempFilename) = createTempFile("stdlog_test", ".tmp.log")
fileLogger = newFileLogger(tempFile, flushThreshold = lvlAll)
addHandler(fileLogger)
teardown:
removeHandler(fileLogger)
try: close(tempFile)
except Exception: discard
removeFile(tempFilename)
test "forwards to std logging":
ls.addAppender(initStdLoggingAppender())
let logger = ls.getLogger("test")
logger.debug("message at debug")
logger.info("message at info")
logger.error("message at error")
tempFile.flushFile()
close(tempFile)
check open(tempFile, tempFilename, fmRead)
let lines = toSeq(lines(tempFile))
check:
lines.len == 3
lines[0] == "DEBUG [test] message at debug"
lines[1] == "INFO [test] message at info"
lines[2] == "ERROR [test] message at error"
test "fallbackOnly works when on":
ls.addAppender(initStdLoggingAppender())
let logger = ls.getLogger("test")
logger.debug("message at debug")
logger.info("message at info")
logger.error("message at error")
let loggedMsgs = initLoggedMessages()
ls.addAppender(initTestLogAppender(loggedMsgs))
logger.notice("message at notice")
logger.warn("message at warn")
logger.fatal("message at fatal")
tempFile.flushFile()
close(tempFile)
check open(tempFile, tempFilename, fmRead)
let lines = toSeq(lines(tempFile))
let lm = loggedMsgs.get()
check:
lines.len == 3
lines[0] == "DEBUG [test] message at debug"
lines[1] == "INFO [test] message at info"
lines[2] == "ERROR [test] message at error"
lm.len == 3
lm[0].message.contains("message at notice")
lm[1].message.contains("message at warn")
lm[2].message.contains("message at fatal")
test "fallbackOnly works when off":
ls.addAppender(initStdLoggingAppender(fallbackOnly = false))
let logger = ls.getLogger("test")
logger.debug("message at debug")
logger.info("message at info")
logger.error("message at error")
let loggedMsgs = initLoggedMessages()
ls.addAppender(initTestLogAppender(loggedMsgs))
logger.notice("message at notice")
logger.warn("message at warn")
logger.fatal("message at fatal")
tempFile.flushFile()
close(tempFile)
check open(tempFile, tempFilename, fmRead)
let lines = toSeq(lines(tempFile))
let lm = loggedMsgs.get()
check:
lines.len == 6
lines[0] == "DEBUG [test] message at debug"
lines[1] == "INFO [test] message at info"
lines[2] == "ERROR [test] message at error"
lines[3] == "NOTICE [test] message at notice"
lines[4] == "WARN [test] message at warn"
lines[5] == "FATAL [test] message at fatal"
lm.len == 3
lm[0].message.contains("message at notice")
lm[1].message.contains("message at warn")
lm[2].message.contains("message at fatal")

98
src/namespaced_logging/autoconfigured.nim Normal file
View File

@ -0,0 +1,98 @@
import std/[json, options]
from logging import Level
import ../namespaced_logging
export
# Types
Level,
Logger,
LogAppender,
LogMessage,
ConsoleLogAppender,
CustomLogAppender,
CustomLogAppenderFunction,
FileLogAppender,
# Procs/Funcs
`%`,
initConsoleLogAppender,
initCustomLogAppender,
initFileLogAppender,
formatJsonStructuredLog
var globalLogServiceRef: ThreadLocalLogService = new(LogService)
globalLogServiceRef[] = initLogService()
var threadLocalLogServiceRef {.threadvar.}: ThreadLocalLogService
var defaultLogger {.threadvar.}: Option[Logger]
proc getThreadLocalLogServiceRef(): ThreadLocalLogService {.inline.} =
if threadLocalLogServiceRef.isNil:
threadLocalLogServiceRef = new(LogService)
threadLocalLogServiceRef[] = globalLogServiceRef[]
return threadLocalLogServiceRef
proc getDefaultLogger(): Logger {.inline.} =
if defaultLogger.isNone:
defaultLogger = some(getThreadLocalLogServiceRef().getLogger(""))
return defaultLogger.get
proc useForAutoconfiguredLogging*(ls: LogService) =
globalLogServiceRef[] = ls
proc setRootLoggingThreshold*(lvl: Level) =
setRootThreshold(getThreadLocalLogServiceRef(), lvl)
proc setLoggingThreshold*(scope: string, lvl: Level) =
setThreshold(getThreadLocalLogServiceRef(), scope, lvl)
proc addLogAppender*(appender: LogAppender) =
addAppender(getThreadLocalLogServiceRef(), appender)
proc getLogger*(scope: string, lvl: Option[Level] = none[Level]()): Logger =
getLogger(getThreadLocalLogServiceRef(), scope, lvl)
proc log*(lvl: Level, msg: string) = getDefaultLogger().log(lvl, msg)
proc log*(lvl: Level, msg: JsonNode) = getDefaultLogger().log(lvl, msg)
proc log*(lvl: Level, error: ref Exception, msg: string) =
getDefaultLogger().log(lvl, error, msg)
template debug*[T](msg: T) = log(lvlDebug, msg)
template info*[T](msg: T) = log(lvlInfo, msg)
template notice*[T](msg: T) = log(lvlNotice, msg)
template warn*[T](msg: T) = log(lvlWarn, msg)
template error*[T](msg: T) = log(lvlError, msg)
template error*(error: ref Exception, msg: string) = log(lvlError, error, msg)
template fatal*[T](msg: T) = log(lvlFatal, msg)
template fatal*(error: ref Exception, msg: string) = log(lvlFatal, error, msg)
when isMainModule:
import std/unittest
import ./testutil
suite "Autoconfigured Logging":
setup:
globalLogServiceRef[] = initLogService()
let loggedMessages = initLoggedMessages()
let testAppender = initTestLogAppender(loggedMessages)
test "simple no-config logging":
addLogAppender(testAppender)
info("test message")
let lm = loggedMessages.get()
check:
lm.len == 1
lm[0].level == lvlInfo
lm[0].message == "test message"