rocksdb/java/rocksjni/loggerjnicallback.cc
fyrz 57f2a00c6f RocksJava - JNI Logger callback
Summary:
Within this commit a new AbstractLogger was introduced
which allows to handle log messages at an application level.

Log messages are passed up to Java using a JNI callback.

This allows a Java-Developer to use common Java APIs for log
messages e.g. SLF4J, LOG4J, etc. Within this commit no new
dependencies were introduced, which keeps the RocksDB API clean
and doesn`t force a developer to use a predefined high-level Java API.

Another feature is to dynamically set a custom loggers verbosity at
runtime using its public method `setInfoLogLevel` and to retrieve
the currently active level using the `infoLogLevel` method.

Test Plan:
make clean jclean rocksdbjava jtest
mvn -f rocksjni.pom package

Reviewers: adamretter, ankgup87, yhchiang

Subscribers: dhruba

Differential Revision: https://reviews.facebook.net/D34755
2015-03-14 20:57:18 +01:00

196 lines
5.8 KiB
C++

// Copyright (c) 2015, Facebook, Inc. All rights reserved.
// This source code is licensed under the BSD-style license found in the
// LICENSE file in the root directory of this source tree. An additional grant
// of patent rights can be found in the PATENTS file in the same directory.
//
// This file implements the callback "bridge" between Java and C++ for
// rocksdb::Logger.
#include "include/org_rocksdb_Logger.h"
#include "rocksjni/loggerjnicallback.h"
#include "rocksjni/portal.h"
namespace rocksdb {
LoggerJniCallback::LoggerJniCallback(
JNIEnv* env, jobject jlogger) {
const jint rs = env->GetJavaVM(&m_jvm);
assert(rs == JNI_OK);
// Note: we want to access the Java Logger instance
// across multiple method calls, so we create a global ref
m_jLogger = env->NewGlobalRef(jlogger);
m_jLogMethodId = LoggerJni::getLogMethodId(env);
}
/**
* Get JNIEnv for current native thread
*/
JNIEnv* LoggerJniCallback::getJniEnv() const {
JNIEnv *env;
jint rs = m_jvm->AttachCurrentThread(reinterpret_cast<void **>(&env), NULL);
assert(rs == JNI_OK);
return env;
}
void LoggerJniCallback::Logv(const char* format, va_list ap) {
// We implement this method because it is virtual but we don't
// use it because we need to know about the log level.
}
void LoggerJniCallback::Logv(const InfoLogLevel log_level,
const char* format, va_list ap) {
if (GetInfoLogLevel() <= log_level) {
JNIEnv* env = getJniEnv();
// determine InfoLogLevel java enum instance
jobject jlog_level;
switch (log_level) {
case rocksdb::InfoLogLevel::DEBUG_LEVEL:
jlog_level = InfoLogLevelJni::DEBUG_LEVEL(env);
break;
case rocksdb::InfoLogLevel::INFO_LEVEL:
jlog_level = InfoLogLevelJni::INFO_LEVEL(env);
break;
case rocksdb::InfoLogLevel::ERROR_LEVEL:
jlog_level = InfoLogLevelJni::ERROR_LEVEL(env);
break;
case rocksdb::InfoLogLevel::FATAL_LEVEL:
jlog_level = InfoLogLevelJni::FATAL_LEVEL(env);
break;
default:
jlog_level = InfoLogLevelJni::FATAL_LEVEL(env);
break;
}
// We try twice: the first time with a fixed-size stack allocated buffer,
// and the second time with a much larger dynamically allocated buffer.
char buffer[500];
for (int iter = 0; iter < 2; iter++) {
char* base;
int bufsize;
if (iter == 0) {
bufsize = sizeof(buffer);
base = buffer;
} else {
bufsize = 30000;
base = new char[bufsize];
}
char* p = base;
char* limit = base + bufsize;
// Print the message
if (p < limit) {
va_list backup_ap;
va_copy(backup_ap, ap);
p += vsnprintf(p, limit - p, format, backup_ap);
va_end(backup_ap);
}
// Truncate to available space if necessary
if (p >= limit) {
if (iter == 0) {
continue; // Try again with larger buffer
} else {
p = limit - 1;
}
}
assert(p < limit);
*p++ = '\0';
// pass java string to callback handler
env->CallVoidMethod(
m_jLogger,
m_jLogMethodId,
jlog_level,
env->NewStringUTF(base));
if (base != buffer) {
delete[] base;
}
break;
}
m_jvm->DetachCurrentThread();
}
}
LoggerJniCallback::~LoggerJniCallback() {
JNIEnv* env = getJniEnv();
env->DeleteGlobalRef(m_jLogger);
m_jvm->DetachCurrentThread();
}
} // namespace rocksdb
/*
* Class: org_rocksdb_Logger
* Method: createNewLoggerOptions
* Signature: (J)V
*/
void Java_org_rocksdb_Logger_createNewLoggerOptions(
JNIEnv* env, jobject jobj, jlong joptions) {
rocksdb::LoggerJniCallback* c =
new rocksdb::LoggerJniCallback(env, jobj);
// set log level
c->SetInfoLogLevel(reinterpret_cast<rocksdb::Options*>
(joptions)->info_log_level);
std::shared_ptr<rocksdb::LoggerJniCallback> *pLoggerJniCallback =
new std::shared_ptr<rocksdb::LoggerJniCallback>;
*pLoggerJniCallback = std::shared_ptr<rocksdb::LoggerJniCallback>(c);
rocksdb::LoggerJni::setHandle(env, jobj, pLoggerJniCallback);
}
/*
* Class: org_rocksdb_Logger
* Method: createNewLoggerDbOptions
* Signature: (J)V
*/
void Java_org_rocksdb_Logger_createNewLoggerDbOptions(
JNIEnv* env, jobject jobj, jlong jdb_options) {
rocksdb::LoggerJniCallback* c =
new rocksdb::LoggerJniCallback(env, jobj);
// set log level
c->SetInfoLogLevel(reinterpret_cast<rocksdb::DBOptions*>
(jdb_options)->info_log_level);
std::shared_ptr<rocksdb::LoggerJniCallback> *pLoggerJniCallback =
new std::shared_ptr<rocksdb::LoggerJniCallback>;
*pLoggerJniCallback = std::shared_ptr<rocksdb::LoggerJniCallback>(c);
rocksdb::LoggerJni::setHandle(env, jobj, pLoggerJniCallback);
}
/*
* Class: org_rocksdb_Logger
* Method: setInfoLogLevel
* Signature: (JB)V
*/
void Java_org_rocksdb_Logger_setInfoLogLevel(
JNIEnv* env, jobject jobj, jlong jhandle, jbyte jlog_level) {
std::shared_ptr<rocksdb::LoggerJniCallback> *handle =
reinterpret_cast<std::shared_ptr<rocksdb::LoggerJniCallback> *>(jhandle);
(*handle)->SetInfoLogLevel(static_cast<rocksdb::InfoLogLevel>(jlog_level));
}
/*
* Class: org_rocksdb_Logger
* Method: infoLogLevel
* Signature: (J)B
*/
jbyte Java_org_rocksdb_Logger_infoLogLevel(
JNIEnv* env, jobject jobj, jlong jhandle) {
std::shared_ptr<rocksdb::LoggerJniCallback> *handle =
reinterpret_cast<std::shared_ptr<rocksdb::LoggerJniCallback> *>(jhandle);
return static_cast<jbyte>((*handle)->GetInfoLogLevel());
}
/*
* Class: org_rocksdb_Logger
* Method: disposeInternal
* Signature: (J)V
*/
void Java_org_rocksdb_Logger_disposeInternal(
JNIEnv* env, jobject jobj, jlong jhandle) {
std::shared_ptr<rocksdb::LoggerJniCallback> *handle =
reinterpret_cast<std::shared_ptr<rocksdb::LoggerJniCallback> *>(jhandle);
handle->reset();
}