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Diffstat (limited to 'java/com/google/android/libraries/mobiledatadownload/internal/logging/LogSampler.java')
-rw-r--r--java/com/google/android/libraries/mobiledatadownload/internal/logging/LogSampler.java217
1 files changed, 109 insertions, 108 deletions
diff --git a/java/com/google/android/libraries/mobiledatadownload/internal/logging/LogSampler.java b/java/com/google/android/libraries/mobiledatadownload/internal/logging/LogSampler.java
index 6e6ac72..b25028c 100644
--- a/java/com/google/android/libraries/mobiledatadownload/internal/logging/LogSampler.java
+++ b/java/com/google/android/libraries/mobiledatadownload/internal/logging/LogSampler.java
@@ -24,7 +24,6 @@ import com.google.common.base.Optional;
import com.google.common.util.concurrent.ListenableFuture;
import com.google.errorprone.annotations.CheckReturnValue;
import com.google.mobiledatadownload.LogProto.StableSamplingInfo;
-import com.google.protobuf.Timestamp;
import java.util.Random;
@@ -32,121 +31,123 @@ import java.util.Random;
@CheckReturnValue
public final class LogSampler {
- private final Flags flags;
- private final Random random;
+ private final Flags flags;
+ private final Random random;
- /**
- * Construct the log sampler.
- *
- * @param flags used to check whether stable sampling is enabled.
- * @param random used to generate random numbers for event based sampling only.
- */
- public LogSampler(Flags flags, Random random) {
- this.flags = flags;
- this.random = random;
- }
-
- /**
- * Determines whether the event should be logged. If the event should be logged it returns an
- * instance of Void that should be attached to the log events.
- *
- * <p>If stable sampling is enabled, this is deterministic. If stable sampling is disabled, the
- * result can change on each call based on the provided Random instance.
- *
- * @param sampleInterval the inverse sampling rate to use. This is controlled by flags per
- * event-type. For stable sampling it's expected that 100 % sampleInterval == 0.
- * @param loggingStateStore used to read persisted random number when stable sampling is enabled.
- * If it is absent, stable sampling will not be used.
- * @return a future of an optional of StableSamplingInfo. The future will resolve to an absent
- * Optional if the event should not be logged. If the event should be logged, the returned
- * Void should be attached to the log event.
- */
- public ListenableFuture<Optional<StableSamplingInfo>> shouldLog(
- long sampleInterval, Optional<LoggingStateStore> loggingStateStore) {
- if (sampleInterval == 0L) {
- return immediateFuture(Optional.absent());
- } else if (sampleInterval < 0L) {
- LogUtil.e("Bad sample interval (negative number): %d", sampleInterval);
- return immediateFuture(Optional.absent());
- } else if (flags.enableRngBasedDeviceStableSampling() && loggingStateStore.isPresent()) {
- return shouldLogDeviceStable(sampleInterval, loggingStateStore.get());
- } else {
- return shouldLogPerEvent(sampleInterval);
+ /**
+ * Construct the log sampler.
+ *
+ * @param flags used to check whether stable sampling is enabled.
+ * @param random used to generate random numbers for event based sampling only.
+ */
+ public LogSampler(Flags flags, Random random) {
+ this.flags = flags;
+ this.random = random;
}
- }
- /**
- * Returns standard random event based sampling.
- *
- * @return if the event should be sampled, returns the Void with stable_sampling_used = false.
- * Otherwise, returns an empty Optional.
- */
- private ListenableFuture<Optional<StableSamplingInfo>> shouldLogPerEvent(long sampleInterval) {
- if (shouldSamplePerEvent(sampleInterval)) {
- return immediateFuture(
- Optional.of(StableSamplingInfo.newBuilder().setStableSamplingUsed(false).build()));
- } else {
- return immediateFuture(Optional.absent());
+ /**
+ * Determines whether the event should be logged. If the event should be logged it returns an
+ * instance of StableSamplingInfo that should be attached to the log events.
+ *
+ * <p>If stable sampling is enabled, this is deterministic. If stable sampling is disabled, the
+ * result can change on each call based on the provided Random instance.
+ *
+ * @param sampleInterval the inverse sampling rate to use. This is controlled by flags per
+ * event-type. For stable sampling it's expected that 100 %
+ * sampleInterval == 0.
+ * @param loggingStateStore used to read persisted random number when stable sampling is
+ * enabled.
+ * If it is absent, stable sampling will not be used.
+ * @return a future of an optional of StableSamplingInfo. The future will resolve to an absent
+ * Optional if the event should not be logged. If the event should be logged, the returned
+ * StableSamplingInfo should be attached to the log event.
+ */
+ public ListenableFuture<Optional<StableSamplingInfo>> shouldLog(
+ long sampleInterval, Optional<LoggingStateStore> loggingStateStore) {
+ if (sampleInterval == 0L) {
+ return immediateFuture(Optional.absent());
+ } else if (sampleInterval < 0L) {
+ LogUtil.e("Bad sample interval (negative number): %d", sampleInterval);
+ return immediateFuture(Optional.absent());
+ } else if (flags.enableRngBasedDeviceStableSampling() && loggingStateStore.isPresent()) {
+ return shouldLogDeviceStable(sampleInterval, loggingStateStore.get());
+ } else {
+ return shouldLogPerEvent(sampleInterval);
+ }
}
- }
- private boolean shouldSamplePerEvent(long sampleInterval) {
- if (sampleInterval == 0L) {
- return false;
- } else if (sampleInterval < 0L) {
- LogUtil.e("Bad sample interval (negative number): %d", sampleInterval);
- return false;
- } else {
- return isPartOfSample(random.nextLong(), sampleInterval);
+ /**
+ * Returns standard random event based sampling.
+ *
+ * @return if the event should be sampled, returns the StableSamplingInfo with
+ * stable_sampling_used = false. Otherwise, returns an empty Optional.
+ */
+ private ListenableFuture<Optional<StableSamplingInfo>> shouldLogPerEvent(long sampleInterval) {
+ if (shouldSamplePerEvent(sampleInterval)) {
+ return immediateFuture(
+ Optional.of(
+ StableSamplingInfo.newBuilder().setStableSamplingUsed(false).build()));
+ } else {
+ return immediateFuture(Optional.absent());
+ }
}
- }
- /**
- * Returns device stable sampling.
- *
- * @return if the event should be sampled, returns the Void with stable_sampling_used = true and
- * all other fields populated. Otherwise, returns an empty Optional.
- */
- private ListenableFuture<Optional<StableSamplingInfo>> shouldLogDeviceStable(
- long sampleInterval, LoggingStateStore loggingStateStore) {
- return PropagatedFluentFuture.from(loggingStateStore.getStableSamplingInfo())
- .transform(
- samplingInfo -> {
- boolean invalidSamplingRateUsed = ((100 % sampleInterval) != 0);
- if (invalidSamplingRateUsed) {
- LogUtil.e(
- "Bad sample interval (1 percent cohort will not log): %d", sampleInterval);
- }
+ private boolean shouldSamplePerEvent(long sampleInterval) {
+ if (sampleInterval == 0L) {
+ return false;
+ } else if (sampleInterval < 0L) {
+ LogUtil.e("Bad sample interval (negative number): %d", sampleInterval);
+ return false;
+ } else {
+ return isPartOfSample(random.nextLong(), sampleInterval);
+ }
+ }
- if (!isPartOfSample(samplingInfo.getStableLogSamplingSalt(), sampleInterval)) {
- return Optional.absent();
- }
+ /**
+ * Returns device stable sampling.
+ *
+ * @return if the event should be sampled, returns the StableSamplingInfo with
+ * stable_sampling_used = true and all other fields populated. Otherwise, returns an empty
+ * Optional.
+ */
+ private ListenableFuture<Optional<StableSamplingInfo>> shouldLogDeviceStable(
+ long sampleInterval, LoggingStateStore loggingStateStore) {
+ return PropagatedFluentFuture.from(loggingStateStore.getStableSamplingInfo())
+ .transform(
+ samplingInfo -> {
+ boolean invalidSamplingRateUsed = ((100 % sampleInterval) != 0);
+ if (invalidSamplingRateUsed) {
+ LogUtil.e(
+ "Bad sample interval (1 percent cohort will not log): %d",
+ sampleInterval);
+ }
- return Optional.of(
- StableSamplingInfo.newBuilder()
- .setStableSamplingUsed(true)
- .setStableSamplingFirstEnabledTimestampMs(
- toMillis(samplingInfo.getLogSamplingSaltSetTimestamp()))
- .setPartOfAlwaysLoggingGroup(
- isPartOfSample(
- samplingInfo.getStableLogSamplingSalt(), /*sampleInterval=*/ 100))
- .setInvalidSamplingRateUsed(invalidSamplingRateUsed)
- .build());
- },
- directExecutor());
- }
+ if (!isPartOfSample(samplingInfo.getStableLogSamplingSalt(),
+ sampleInterval)) {
+ return Optional.absent();
+ }
- /**
- * Returns whether this device is part of the sample with the given sampling rate and random
- * number.
- */
- private boolean isPartOfSample(long randomNumber, long sampleInterval) {
- return randomNumber % sampleInterval == 0;
- }
+ return Optional.of(
+ StableSamplingInfo.newBuilder()
+ .setStableSamplingUsed(true)
+ .setStableSamplingFirstEnabledTimestampMs(
+ TimestampsUtil.toMillis(
+ samplingInfo.getLogSamplingSaltSetTimestamp()))
+ .setPartOfAlwaysLoggingGroup(
+ isPartOfSample(
+ samplingInfo.getStableLogSamplingSalt(), /* sampleInterval= */
+ 100))
+ .setInvalidSamplingRateUsed(invalidSamplingRateUsed)
+ .build());
+ },
+ directExecutor());
+ }
- // Copy from com.google.protobuf.util.Timestamps
- // TODO(b/243397277) Remove toMillis.
- private static long toMillis(Timestamp timestamp) {
- return timestamp.getSeconds() * 1000L + (long)timestamp.getNanos() / 1000000L;
- }
-} \ No newline at end of file
+ /**
+ * Returns whether this device is part of the sample with the given sampling rate and random
+ * number.
+ */
+ private boolean isPartOfSample(long randomNumber, long sampleInterval) {
+ return randomNumber % sampleInterval == 0;
+ }
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-07-22 22:29:39 +0000