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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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package jdk.jfr.internal.jfc;

import java.io.IOException;
import java.io.InputStream;
import java.io.Reader;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.NoSuchFileException;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.text.ParseException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

import jdk.jfr.Configuration;
import jdk.jfr.internal.LogLevel;
import jdk.jfr.internal.LogTag;
import jdk.jfr.internal.Logger;
import jdk.jfr.internal.SecuritySupport;
import jdk.jfr.internal.SecuritySupport.SafePath;

Configuration factory for JFC files. *
/** * {@link Configuration} factory for JFC files. * */
public final class JFC { private static final int BUFFER_SIZE = 8192; private static final int MAXIMUM_FILE_SIZE = 1024 * 1024; private static final int MAX_BUFFER_SIZE = Integer.MAX_VALUE - 8; private static volatile List<KnownConfiguration> knownConfigurations;
Reads a known configuration file (located into a string, but doesn't parse it until it's being used.
/** * Reads a known configuration file (located into a string, but doesn't * parse it until it's being used. */
private static final class KnownConfiguration { private final String content; private final String filename; private final String name; private Configuration configuration; public KnownConfiguration(SafePath knownPath) throws IOException { this.content = readContent(knownPath); this.name = nameFromPath(knownPath.toPath()); this.filename = nullSafeFileName(knownPath.toPath()); } public boolean isNamed(String name) { return filename.equals(name) || this.name.equals(name); } public Configuration getConfigurationFile() throws IOException, ParseException { if (configuration == null) { configuration = JFCParser.createConfiguration(name, content); } return configuration; } public String getName() { return name; } private static String readContent(SafePath knownPath) throws IOException { if (SecuritySupport.getFileSize(knownPath) > MAXIMUM_FILE_SIZE) { throw new IOException("Configuration with more than " + MAXIMUM_FILE_SIZE + " characters can't be read."); } try (InputStream r = SecuritySupport.newFileInputStream(knownPath)) { return JFC.readContent(r); } } } private JFC() { // private utility class }
Reads a configuration from a file.
Params:
  • path – the file containing the configuration, not null
Throws:
See Also:
Returns:Configuration, not null
/** * Reads a configuration from a file. * * @param path the file containing the configuration, not {@code null} * @return {@link Configuration}, not {@code null} * @throws ParseException if the file can't be parsed * @throws IOException if the file can't be read * * @throws SecurityException if a security manager exists and its * {@code checkRead} method denies read access to the file * @see java.io.File#getPath() * @see java.lang.SecurityManager#checkRead(java.lang.String) */
public static Configuration create(String name, Reader reader) throws IOException, ParseException { return JFCParser.createConfiguration(name, reader); } private static String nullSafeFileName(Path file) throws IOException { Path filename = file.getFileName(); if (filename == null) { throw new IOException("Path has no file name"); } return filename.toString(); } public static String nameFromPath(Path file) throws IOException { String f = nullSafeFileName(file); if (f.endsWith(JFCParser.FILE_EXTENSION)) { return f.substring(0, f.length() - JFCParser.FILE_EXTENSION.length()); } else { return f; } } // Invoked by DCmdStart public static Configuration createKnown(String name) throws IOException, ParseException { // Known name, no need for permission for (KnownConfiguration known : getKnownConfigurations()) { if (known.isNamed(name)) { return known.getConfigurationFile(); } } // Check JFC directory SafePath path = SecuritySupport.JFC_DIRECTORY; if (path != null && SecuritySupport.exists(path)) { for (String extension : Arrays.asList("", JFCParser.FILE_EXTENSION)) { SafePath file = new SafePath(path.toPath().resolveSibling(name + extension)); if (SecuritySupport.exists(file) && !SecuritySupport.isDirectory(file)) { try (Reader r = SecuritySupport.newFileReader(file)) { String jfcName = nameFromPath(file.toPath()); return JFCParser.createConfiguration(jfcName, r); } } } } // Assume path included in name Path localPath = Paths.get(name); String jfcName = nameFromPath(localPath); try (Reader r = Files.newBufferedReader(localPath)) { return JFCParser.createConfiguration(jfcName, r); } } private static String readContent(InputStream source) throws IOException { byte[] bytes = read(source, BUFFER_SIZE); return new String(bytes, StandardCharsets.UTF_8); } // copied from java.io.file.Files to avoid dependency on JDK 9 code private static byte[] read(InputStream source, int initialSize) throws IOException { int capacity = initialSize; byte[] buf = new byte[capacity]; int nread = 0; int n; for (;;) { // read to EOF which may read more or less than initialSize (eg: file // is truncated while we are reading) while ((n = source.read(buf, nread, capacity - nread)) > 0) nread += n; // if last call to source.read() returned -1, we are done // otherwise, try to read one more byte; if that failed we're done too if (n < 0 || (n = source.read()) < 0) break; // one more byte was read; need to allocate a larger buffer if (capacity <= MAX_BUFFER_SIZE - capacity) { capacity = Math.max(capacity << 1, BUFFER_SIZE); } else { if (capacity == MAX_BUFFER_SIZE) throw new OutOfMemoryError("Required array size too large"); capacity = MAX_BUFFER_SIZE; } buf = Arrays.copyOf(buf, capacity); buf[nread++] = (byte)n; } return (capacity == nread) ? buf : Arrays.copyOf(buf, nread); }
Returns list of predefined configurations available.
Returns:list of configurations, not null
/** * Returns list of predefined configurations available. * * @return list of configurations, not null */
public static List<Configuration> getConfigurations() { List<Configuration> configs = new ArrayList<>(); for (KnownConfiguration knownConfig : getKnownConfigurations()) { try { configs.add(knownConfig.getConfigurationFile()); } catch (IOException e) { Logger.log(LogTag.JFR, LogLevel.WARN, "Could not load configuration " + knownConfig.getName() + ". " + e.getMessage()); } catch (ParseException e) { Logger.log(LogTag.JFR, LogLevel.WARN, "Could not parse configuration " + knownConfig.getName() + ". " + e.getMessage()); } } return configs; } private static List<KnownConfiguration> getKnownConfigurations() { if (knownConfigurations == null) { List<KnownConfiguration> configProxies = new ArrayList<>(); for (SafePath p : SecuritySupport.getPredefinedJFCFiles()) { try { configProxies.add(new KnownConfiguration(p)); } catch (IOException ioe) { // ignore } } knownConfigurations = configProxies; } return knownConfigurations; } public static Configuration getPredefined(String name) throws IOException, ParseException { for (KnownConfiguration knownConfig : getKnownConfigurations()) { if (knownConfig.getName().equals(name)) { return knownConfig.getConfigurationFile(); } } throw new NoSuchFileException("Could not locate configuration with name " + name); } }