From 9fa2b5ae833bef734dcd219771d901c0310cfb3b Mon Sep 17 00:00:00 2001
From: Paul Draper <paul@lucidchart.com>
Date: Sun, 5 Mar 2017 23:25:58 -0700
Subject: [PATCH] ThreadContextSpan

---
 .travis.yml                                   | 28 ++++++++++++++
 build.sbt                                     | 26 +++++++++++++
 project/build.properties                      |  1 +
 project/build.sbt                             |  3 ++
 thread-context/build.sbt                      |  7 ++++
 .../threadcontext/ThreadContextSpan.java      | 37 +++++++++++++++++++
 6 files changed, 102 insertions(+)
 create mode 100644 .travis.yml
 create mode 100644 build.sbt
 create mode 100644 project/build.properties
 create mode 100644 project/build.sbt
 create mode 100644 thread-context/build.sbt
 create mode 100644 thread-context/src/main/java/io/opentracing/threadcontext/ThreadContextSpan.java

diff --git a/.travis.yml b/.travis.yml
new file mode 100644
index 0000000..ed0c9aa
--- /dev/null
+++ b/.travis.yml
@@ -0,0 +1,28 @@
+after_success: |
+  if [ "$TRAVIS_SECURE_ENV_VARS" == true ]; then
+    echo "$PGP_SECRET" | base64 --decode | gpg --import
+    if [ -z "$TRAVIS_TAG" ]; then
+        sbt publishSigned
+    else
+        sbt publishSigned sonatypeRelease
+    fi
+  fi
+cache:
+  directories:
+    - $HOME/.ivy2
+    - $HOME/.sbt
+deploy:
+  api_key: $GITHUB_AUTH
+  file: '*/target/**/*.jar'
+  file_glob: true
+  on:
+    tags: true
+  provider: releases
+  skip_cleanup: true
+git:
+  depth: 1
+jdk: oraclejdk8
+language: scala
+script:
+  - '[ "$TRAVIS_PULL_REQUEST" != false ] || export SBT_OPTS=-Dbuild.version=${TRAVIS_TAG:-$TRAVIS_BRANCH-SNAPSHOT}'
+  - sbt package
diff --git a/build.sbt b/build.sbt
new file mode 100644
index 0000000..3ef84aa
--- /dev/null
+++ b/build.sbt
@@ -0,0 +1,26 @@
+lazy val `thread-context` = project
+
+inScope(Global)(Seq(
+  autoScalaLibrary := false,
+  credentials += Credentials(
+    "Sonatype Nexus Repository Manager",
+    "oss.sonatype.org",
+    sys.env.getOrElse("SONATYPE_USERNAME", ""),
+    sys.env.getOrElse("SONATYPE_PASSWORD", "")
+  ),
+  crossPaths := false,
+  developers += Developer("pauldraper", "Paul Draper", "paulddraper@gmail.com", url("https://github.com/pauldraper")),
+  homepage := Some(url("https://git.lucidchart.com/lucidsoftware/opentracing-thread-context")),
+  licenses += "Apache 2.0 License" -> url("https://www.apache.org/licenses/LICENSE-2.0"),
+  organization := "com.lucidchart",
+  organizationHomepage := Some(url("https://github.com/lucidsoftware")),
+  organizationName := "Lucid Software",
+  PgpKeys.pgpPassphrase := Some(Array.emptyCharArray),
+  resolvers += Resolver.typesafeRepo("releases"),
+  scmInfo := Some(ScmInfo(
+    url("https://github.com/lucidsoftware/opentracing-thread-context"),
+    "scm:git:git@github.com:lucidsoftware/opentracing-thread-context"
+  )),
+  startYear := Some(2017),
+  version := sys.props.getOrElse("build.version", "0-SNAPSHOT")
+))
diff --git a/project/build.properties b/project/build.properties
new file mode 100644
index 0000000..27e88aa
--- /dev/null
+++ b/project/build.properties
@@ -0,0 +1 @@
+sbt.version=0.13.13
diff --git a/project/build.sbt b/project/build.sbt
new file mode 100644
index 0000000..8e1620a
--- /dev/null
+++ b/project/build.sbt
@@ -0,0 +1,3 @@
+addSbtPlugin("com.jsuereth" % "sbt-pgp" % "1.0.0")
+
+addSbtPlugin("org.xerial.sbt" % "sbt-sonatype" % "1.1")
diff --git a/thread-context/build.sbt b/thread-context/build.sbt
new file mode 100644
index 0000000..e30e5bb
--- /dev/null
+++ b/thread-context/build.sbt
@@ -0,0 +1,7 @@
+libraryDependencies ++= Seq(
+  "com.lucidchart" % "thread-context" % "0.4",
+  "io.opentracing" % "opentracing-api" % "0.20.7",
+  "io.opentracing" % "opentracing-noop" % "0.20.7"
+)
+
+name := s"opentracing-${name.value}"
diff --git a/thread-context/src/main/java/io/opentracing/threadcontext/ThreadContextSpan.java b/thread-context/src/main/java/io/opentracing/threadcontext/ThreadContextSpan.java
new file mode 100644
index 0000000..91326e1
--- /dev/null
+++ b/thread-context/src/main/java/io/opentracing/threadcontext/ThreadContextSpan.java
@@ -0,0 +1,37 @@
+package io.opentracing.threadcontext;
+
+import com.github.threadcontext.ThreadContext;
+import com.github.threadcontext.ThreadLocalSaver;
+import io.opentracing.NoopSpan;
+import io.opentracing.Span;
+import java.util.function.Supplier;
+
+public final class ThreadContextSpan {
+
+    private static final ThreadLocal<Span> span = new ThreadLocal<Span>() {
+        protected Span initialValue() {
+            return defaultSpan.get();
+        }
+    };
+    static {
+        ThreadContext.savers.add(new ThreadLocalSaver<>(span));
+    }
+
+    public static Supplier<Span> defaultSpan = () -> NoopSpan.INSTANCE;
+
+    private ThreadContextSpan() {
+    }
+
+    public static Span get() {
+        return span.get();
+    }
+
+    public static void set(Span span) {
+        ThreadContextSpan.span.set(span);
+    }
+
+    public static void clear() {
+        span.remove();
+    }
+
+}