Fix for cache init on existing directories (#1743)

* Add tests+fix for cache init on existing directories

* Clear the cache if it is the wrong version

* Link to FHIR spec docs for .index.json

org.hl7.fhir.utilities/src/main/java/org/hl7/fhir/utilities/npm/FilesystemPackageCacheManager.java

@@ -210,26 +210,30 @@ public class FilesystemPackageCacheManager extends BasePackageCacheManager imple
         Utilities.createDirectory(cacheFolder.getAbsolutePath());
         createIniFile();
       } else {
-        if (!isCacheFolderValid()) {
+        if (!iniFileExists()) {
+          createIniFile();
+        }
+        if (!isIniFileCurrentVersion()) {
           clearCache();
           createIniFile();
-        } else {
-          deleteOldTempDirectories();
         }
+        deleteOldTempDirectories();
       }
       return null;
     });
   }
 
-  private boolean isCacheFolderValid() throws IOException {
+  private boolean iniFileExists() throws IOException {
     String iniPath = getPackagesIniPath();
     File iniFile = ManagedFileAccess.file(iniPath);
-    if (!(iniFile.exists())) {
+    return iniFile.exists();
-      return false;
+  }
-    }
+
+  private boolean isIniFileCurrentVersion() throws IOException {
+    String iniPath = getPackagesIniPath();
     IniFile ini = new IniFile(iniPath);
-    String v = ini.getStringProperty("cache", "version");
+    String version = ini.getStringProperty("cache", "version");
-    return CACHE_VERSION.equals(v);
+    return CACHE_VERSION.equals(version);
   }
 
   private void deleteOldTempDirectories() throws IOException {

org.hl7.fhir.utilities/src/main/java/org/hl7/fhir/utilities/npm/NpmPackage.java

@@ -648,7 +648,17 @@ public class NpmPackage {
   }
 
 
-
+  /**
+   * Create a package .index.json file for a package folder.
+   * <p>
+   * See <a href="https://hl7.org/fhir/packages.html#2.1.10.4">the FHIR specification</a> for details on .index.json
+   * format and usage.
+   *
+   * @param desc
+   * @param folder
+   * @throws FileNotFoundException
+   * @throws IOException
+   */
   public void indexFolder(String desc, NpmPackageFolder folder) throws FileNotFoundException, IOException {
     List<String> remove = new ArrayList<>();
     NpmPackageIndexBuilder indexer = new NpmPackageIndexBuilder();

org.hl7.fhir.utilities/src/test/java/org/hl7/fhir/utilities/npm/FilesystemPackageManagerTests.java

@@ -1,22 +1,25 @@
 package org.hl7.fhir.utilities.npm;
 
+import static org.assertj.core.api.Assertions.assertThat;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 
 import java.io.File;
 
+import java.io.FileWriter;
 import java.io.IOException;
 import java.nio.file.Files;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Random;
+import java.util.UUID;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.stream.Stream;
 
 import javax.annotation.Nonnull;
 
+import org.hl7.fhir.utilities.IniFile;
 import org.hl7.fhir.utilities.filesystem.ManagedFileAccess;
-import org.junit.jupiter.api.RepeatedTest;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.condition.DisabledOnOs;
 import org.junit.jupiter.api.condition.EnabledOnOs;
@@ -100,7 +103,6 @@ public class FilesystemPackageManagerTests {
   @DisabledOnOs(OS.WINDOWS)
   public void testSystemCacheDirectory() throws IOException {
     File folder = new FilesystemPackageCacheManager.Builder().withSystemCacheFolder().getCacheFolder();
-
     assertEquals( "/var/lib/.fhir/packages", folder.getAbsolutePath());
   }
 
@@ -124,6 +126,118 @@ public class FilesystemPackageManagerTests {
     return params.stream();
   }
 
+  private void createDummyTemp(File cacheDirectory, String lowerCase) throws IOException {
+    createDummyPackage(cacheDirectory, lowerCase);
+  }
+
+  private void createDummyPackage(File cacheDirectory, String packageName, String packageVersion) throws IOException {
+    String directoryName = packageName + "#" + packageVersion;
+    createDummyPackage(cacheDirectory, directoryName);
+  }
+
+  private static void createDummyPackage(File cacheDirectory, String directoryName) throws IOException {
+    File packageDirectory = ManagedFileAccess.file(cacheDirectory.getAbsolutePath(), directoryName);
+    packageDirectory.mkdirs();
+
+    File dummyContentFile = ManagedFileAccess.file(packageDirectory.getAbsolutePath(), "dummy.txt");
+    FileWriter wr = new FileWriter(dummyContentFile);
+    wr.write("Ain't nobody here but us chickens");
+    wr.flush();
+    wr.close();
+  }
+
+  private void assertThatDummyTempExists(File cacheDirectory, String dummyTempPackage) throws IOException {
+    File dummyTempDirectory = ManagedFileAccess.file(cacheDirectory.getAbsolutePath(), dummyTempPackage);
+    assertThat(dummyTempDirectory).exists();
+
+    File dummyContentFile = ManagedFileAccess.file(dummyTempDirectory.getAbsolutePath(), "dummy.txt");
+    assertThat(dummyContentFile).exists();
+  }
+
+  @Test
+  public void testCreatesIniIfDoesntExistAndCacheStaysIntact() throws IOException {
+    File cacheDirectory = ManagedFileAccess.fromPath(Files.createTempDirectory("fpcm-multithreadingTest"));
+    File cacheIni = ManagedFileAccess.file(cacheDirectory.getAbsolutePath(), "packages.ini");
+
+    createDummyPackage(cacheDirectory, "example.fhir.uv.myig", "1.2.3");
+
+    String dummyTempPackage = UUID.randomUUID().toString().toLowerCase();
+    createDummyTemp(cacheDirectory, dummyTempPackage);
+    assertThatDummyTempExists(cacheDirectory, dummyTempPackage);
+
+    assertThat(cacheIni).doesNotExist();
+    FilesystemPackageCacheManager filesystemPackageCacheManager = new FilesystemPackageCacheManager.Builder().withCacheFolder(cacheDirectory.getAbsolutePath()).build();
+    assertInitializedTestCacheIsValid(cacheDirectory, true);
+  }
+
+
+
+  @Test
+  public void testClearsCacheIfVersionIsWrong() throws IOException {
+    File cacheDirectory = ManagedFileAccess.fromPath(Files.createTempDirectory("fpcm-multithreadingTest"));
+    File cacheIni = ManagedFileAccess.file(cacheDirectory.getAbsolutePath(), "packages.ini");
+
+    createDummyPackage(cacheDirectory, "example.fhir.uv.myig", "1.2.3");
+    String dummyTempPackage = UUID.randomUUID().toString().toLowerCase();
+    createDummyTemp(cacheDirectory, dummyTempPackage);
+    assertThatDummyTempExists(cacheDirectory, dummyTempPackage);
+
+
+    IniFile ini = new IniFile(cacheIni.getAbsolutePath());
+    ini.setStringProperty("cache", "version", "2", null);
+    ini.save();
+
+    assertThat(cacheIni).exists();
+    FilesystemPackageCacheManager filesystemPackageCacheManager = new FilesystemPackageCacheManager.Builder().withCacheFolder(cacheDirectory.getAbsolutePath()).build();
+    assertInitializedTestCacheIsValid(cacheDirectory, false);
+  }
+
+  @Test
+  public void testCacheStaysIntactIfVersionIsTheSame() throws IOException {
+    File cacheDirectory = ManagedFileAccess.fromPath(Files.createTempDirectory("fpcm-multithreadingTest"));
+    File cacheIni = ManagedFileAccess.file(cacheDirectory.getAbsolutePath(), "packages.ini");
+
+    createDummyPackage(cacheDirectory, "example.fhir.uv.myig", "1.2.3");
+    String dummyTempPackage = UUID.randomUUID().toString().toLowerCase();
+    createDummyTemp(cacheDirectory, dummyTempPackage);
+    assertThatDummyTempExists(cacheDirectory, dummyTempPackage);
+
+
+    IniFile ini = new IniFile(cacheIni.getAbsolutePath());
+    ini.setStringProperty("cache", "version", "3", null);
+    ini.save();
+
+    assertThat(cacheIni).exists();
+    FilesystemPackageCacheManager filesystemPackageCacheManager = new FilesystemPackageCacheManager.Builder().withCacheFolder(cacheDirectory.getAbsolutePath()).build();
+    assertInitializedTestCacheIsValid(cacheDirectory, true);
+  }
+
+  private void assertInitializedTestCacheIsValid(File cacheDirectory, boolean dummyPackageShouldExist) throws IOException {
+    assertThat(cacheDirectory).exists();
+    File iniFile = ManagedFileAccess.file(cacheDirectory.getAbsolutePath(), "packages.ini");
+    assertThat(ManagedFileAccess.file(cacheDirectory.getAbsolutePath(), "packages.ini")).exists();
+    IniFile ini = new IniFile(iniFile.getAbsolutePath());
+    String version = ini.getStringProperty("cache", "version");
+    assertThat(version).isEqualTo("3");
+
+    File[] files = cacheDirectory.listFiles();
+    if (dummyPackageShouldExist) {
+      // Check that only packages.ini and our dummy package are in the cache. Our previous temp should be deleted.
+      assertThat(files).hasSize(2); // packages.ini and example.fhir.uv.myig#1.2.3 (directory)
+
+      File dummyPackage = ManagedFileAccess.file(cacheDirectory.getAbsolutePath(), "example.fhir.uv.myig#1.2.3");
+      assertThat(dummyPackage).exists();
+
+      File dummyContentFile = ManagedFileAccess.file(dummyPackage.getAbsolutePath(), "dummy.txt");
+      assertThat(dummyContentFile).exists();
+    } else {
+      // Check that only packages.ini is in the cache.
+      assertThat(files).hasSize(1);
+    }
+
+
+  }
+
   @MethodSource("packageCacheMultiThreadTestParams")
   @ParameterizedTest
   public void packageCacheMultiThreadTest(final int threadTotal, final int packageCacheManagerTotal) throws IOException {