1 files changed, 97 insertions, 0 deletions
diff --git a/bundle-plugin/src/main/java/com/yahoo/container/plugin/osgi/ImportPackages.java b/bundle-plugin/src/main/java/com/yahoo/container/plugin/osgi/ImportPackages.java
new file mode 100644
index 00000000000..b58248ec4a6
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+++ b/bundle-plugin/src/main/java/com/yahoo/container/plugin/osgi/ImportPackages.java
@@ -0,0 +1,97 @@
+// Copyright 2018 Yahoo Holdings. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
+package com.yahoo.container.plugin.osgi;
+
+import com.google.common.collect.Sets;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import java.util.Set;
+import java.util.stream.Collectors;
+
+/**
+ * @author Tony Vaagenes
+ * @author ollivir
+ */
+public class ImportPackages {
+    public static final int INFINITE_VERSION = 99999;
+    private static final String GUAVA_BASE_PACKAGE = "com.google.common";
+
+    public static class Import {
+        private final String packageName;
+        private final List<Integer> versionNumber;
+
+        public Import(String packageName, Optional<String> version) {
+            this.packageName = packageName;
+            this.versionNumber = new ArrayList<>();
+
+            if (version.isPresent()) {
+                try {
+                    Arrays.stream(version.get().split("\\.")).map(Integer::parseInt).limit(3).forEach(this.versionNumber::add);
+                } catch (NumberFormatException e) {
+                    throw new IllegalArgumentException(
+                            String.format("Invalid version number '%s' for package '%s'.", version.get(), packageName), e);
+                }
+            }
+        }
+
+        public Optional<Integer> majorVersion() {
+            if (versionNumber.size() >= 1) {
+                return Optional.of(versionNumber.get(0));
+            } else {
+                return Optional.empty();
+            }
+        }
+
+        public String packageName() {
+            return packageName;
+        }
+
+        public String version() {
+            return versionNumber.stream().map(Object::toString).collect(Collectors.joining("."));
+        }
+
+        // TODO: Detecting guava packages should be based on Bundle-SymbolicName, not package name.
+        public Optional<String> importVersionRange() {
+            if (versionNumber.isEmpty()) {
+                return Optional.empty();
+            } else {
+                int upperLimit = isGuavaPackage() ? INFINITE_VERSION // guava increases major version for each release
+                        : versionNumber.get(0) + 1;
+                return Optional.of(String.format("[%s,%d)", version(), upperLimit));
+            }
+        }
+
+        public boolean isGuavaPackage() {
+            return packageName.equals(GUAVA_BASE_PACKAGE) || packageName.startsWith(GUAVA_BASE_PACKAGE + ".");
+        }
+
+        public String asOsgiImport() {
+            return packageName + importVersionRange().map(version -> ";version=\"" + version + '"').orElse("");
+        }
+    }
+
+    public static Map<String, Import> calculateImports(Set<String> referencedPackages, Set<String> implementedPackages,
+            Map<String, ExportPackages.Export> exportedPackages) {
+        Map<String, Import> ret = new HashMap<>();
+        for (String undefinedPackage : Sets.difference(referencedPackages, implementedPackages)) {
+            ExportPackages.Export export = exportedPackages.get(undefinedPackage);
+            if (export != null) {
+                ret.put(undefinedPackage, new Import(undefinedPackage, version(export)));
+            }
+        }
+        return ret;
+    }
+
+    private static Optional<String> version(ExportPackages.Export export) {
+        for (ExportPackages.Parameter param : export.getParameters()) {
+            if ("version".equals(param.getName())) {
+                return Optional.of(param.getValue());
+            }
+        }
+        return Optional.empty();
+    }
+}