1 files changed, 88 insertions, 0 deletions
diff --git a/vendor/jonahgeorge/jaeger-client-php/src/Jaeger/Sampler/ProbabilisticSampler.php b/vendor/jonahgeorge/jaeger-client-php/src/Jaeger/Sampler/ProbabilisticSampler.php
new file mode 100644
index 000000000..cb265d01e
--- /dev/null
+++ b/vendor/jonahgeorge/jaeger-client-php/src/Jaeger/Sampler/ProbabilisticSampler.php
@@ -0,0 +1,88 @@
+<?php
+
+namespace Jaeger\Sampler;
+
+use OutOfBoundsException;
+use const Jaeger\SAMPLER_PARAM_TAG_KEY;
+use const Jaeger\SAMPLER_TYPE_PROBABILISTIC;
+use const Jaeger\SAMPLER_TYPE_TAG_KEY;
+
+/**
+ * A sampler that randomly samples a certain percentage of traces specified
+ * by the samplingRate, in the range between 0.0 and 1.0.
+ *
+ * @package Jaeger\Sampler
+ */
+class ProbabilisticSampler implements SamplerInterface
+{
+    /**
+     * The sampling rate rate between 0.0 and 1.0.
+     *
+     * @var float
+     */
+    private $rate;
+
+    /**
+     * A list of the sampler tags.
+     *
+     * @var array
+     */
+    private $tags = [];
+
+    /**
+     * The boundary of the sample sampling rate.
+     *
+     * @var float
+     */
+    private $boundary;
+
+    /**
+     * ProbabilisticSampler constructor.
+     *
+     * @param float $rate
+     * @throws OutOfBoundsException
+     */
+    public function __construct(float $rate)
+    {
+        $this->tags = [
+            SAMPLER_TYPE_TAG_KEY => SAMPLER_TYPE_PROBABILISTIC,
+            SAMPLER_PARAM_TAG_KEY => $rate,
+        ];
+
+        if ($rate < 0.0 || $rate > 1.0) {
+            throw new OutOfBoundsException('Sampling rate must be between 0.0 and 1.0.');
+        }
+
+        $this->rate = $rate;
+        if ($rate < 0.5) {
+            $this->boundary = (int)($rate * PHP_INT_MAX);
+        } else {
+            // more precise calculation due to int and float having different precision near PHP_INT_MAX
+            $this->boundary = PHP_INT_MAX - (int)((1 - $rate) * PHP_INT_MAX);
+        }
+    }
+
+    /**
+     * {@inheritdoc}
+     *
+     * @param string $traceId   The traceId on the span.
+     * @param string $operation The operation name set on the span.
+     * @return array
+     */
+    public function isSampled(string $traceId, string $operation = ''): array
+    {
+        return [($traceId < $this->boundary), $this->tags];
+    }
+
+    /**
+     * {@inheritdoc}
+     *
+     * Only implemented to satisfy the sampler interface.
+     *
+     * @return void
+     */
+    public function close()
+    {
+        // nothing to do
+    }
+}