centralize state path initialization

nb-api/src/main/java/io/nosqlbench/api/system/NBStatePath.java

@@ -0,0 +1,84 @@
+/*
+ * Copyright (c) 2023 nosqlbench
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.nosqlbench.api.system;
+
+import io.nosqlbench.api.errors.BasicError;
+
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.attribute.PosixFilePermissions;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.stream.Collectors;
+
+public class NBStatePath {
+
+    public static final String NB_STATEDIR_PATHS = "$NBSTATEDIR:$PWD/.nosqlbench:$HOME/.nosqlbench";
+
+    private static final List<String> statePathAccesses = new ArrayList<>();
+    private static Path statepath;
+
+    public static Path initialize() {
+        return initialize(NB_STATEDIR_PATHS);
+    }
+    public static Path initialize(String statedirs) {
+        if (statedirs==null || statedirs.isBlank()) {
+            statedirs = NB_STATEDIR_PATHS;
+        }
+
+        if (statepath!=null) {
+            return statepath;
+        }
+
+        if (0 < statePathAccesses.size())
+            throw new BasicError("The state dir must be set before it is used by other\n" +
+                " options. If you want to change the statedir, be sure you do it before\n" +
+                " dependent options. These parameters were called before this --statedir:\n" +
+                statePathAccesses.stream().map(s -> "> " + s).collect(Collectors.joining("\n")));
+        if (null != statepath) return statepath;
+
+        final List<String> paths = NBEnvironment.INSTANCE.interpolateEach(":", statedirs);
+        Path selected = null;
+
+        for (final String pathName : paths) {
+            final Path path = Path.of(pathName);
+            if (Files.exists(path)) {
+                if (Files.isDirectory(path)) {
+                    selected = path;
+                    break;
+                }
+                System.err.println("ERROR: possible state dir path is not a directory: '" + path + '\'');
+            }
+        }
+        if (null == selected) selected = Path.of(paths.get(paths.size() - 1));
+
+        if (!Files.exists(selected)) try {
+            Files.createDirectories(
+                selected,
+                PosixFilePermissions.asFileAttribute(PosixFilePermissions.fromString("rwxrwx---"))
+            );
+        } catch (final IOException e) {
+            throw new BasicError("Could not create state directory at '" + selected + "': " + e.getMessage());
+        }
+
+        NBEnvironment.INSTANCE.put(NBEnvironment.NBSTATEDIR, selected.toString());
+
+        return selected;
+    }
+
+}