inwc3#62: instrument retry policy

Cokemonkey11 · Mar 28, 2021 · 3bfdb3d · 3bfdb3d
1 parent 251638c
commit 3bfdb3d
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Showing 2 changed files with 68 additions and 37 deletions.
diff --git a/build.gradle b/build.gradle
@@ -35,6 +35,7 @@ dependencies {
     implementation group: 'com.dorkbox', name: 'PeParser-Dorkbox-Util', version: '2.7'
     implementation group: 'com.twelvemonkeys.imageio', name: 'imageio-jpeg', version: '3.6.4'
     implementation 'com.jcraft:jzlib:1.1.3'
+    implementation 'net.jodah:failsafe:2.4.0'
 
     // TestNG
     testImplementation 'org.testng:testng:6.14.3'

diff --git a/src/main/java/net/moonlightflower/wc3libs/bin/GameExe.java b/src/main/java/net/moonlightflower/wc3libs/bin/GameExe.java
@@ -1,6 +1,9 @@
 package net.moonlightflower.wc3libs.bin;
 
 import dorkbox.peParser.PE;
+import net.jodah.failsafe.Failsafe;
+import net.jodah.failsafe.RetryPolicy;
+import net.jodah.failsafe.event.ExecutionCompletedEvent;
 import net.moonlightflower.wc3libs.misc.ProcCaller;
 import net.moonlightflower.wc3libs.port.GameVersion;
 
@@ -12,17 +15,37 @@
 import java.io.*;
 import java.nio.charset.StandardCharsets;
 import java.nio.file.Files;
+import java.time.temporal.ChronoUnit;
 import java.util.Arrays;
-import java.util.Collections;
-import java.util.List;
-import java.util.regex.Matcher;
-import java.util.regex.Pattern;
+
 
 public class GameExe {
     private static final Logger log = LoggerFactory.getLogger(GameExe.class.getName());
 
     @Nonnull
     public static String getVersionString(@Nonnull File file) throws IOException {
+        return Failsafe.with(
+            new RetryPolicy<String>()
+                .handle(IOException.class)
+                .withBackoff(500, 10_000, ChronoUnit.MILLIS)
+                .withMaxRetries(3)
+                .onRetriesExceeded(GameExe::logRetriesExceededGettingVersion)
+        ).get(() -> GameExe.getVersionStringInternal(file));
+    }
+
+    private static void logRetriesExceededGettingVersion(ExecutionCompletedEvent<String> event) {
+        log.warn("Failed to get version string from either dorkbox PE or WMIC. Last event was {}", event);
+    }
+
+    /**
+     * Attempts to read windows exe metadata to obtain version string. Uses dorkbox PE, and falls back to WMIC if there
+     * is an exception.
+     * @param file location of exe
+     * @return version string, e.g. `1.32.9.16589`
+     * @throws IOException if dorkbox PE encounters an exception and then WMIC subsequently fails to emit a version.
+     */
+    @Nonnull
+    private static String getVersionStringInternal(@Nonnull File file) throws IOException {
         try {
             String s = file.getAbsolutePath();
             log.info("Querying {} with dorkbox PE", s);
@@ -31,59 +54,66 @@ public static String getVersionString(@Nonnull File file) throws IOException {
         } catch (Exception e) {
             log.info("Falling back to WMIC due to {}", e);
 
-            File tmpBat = File.createTempFile("getVersionString", "tmp_proxy.bat");
+            return getVersionStringInternalWmic(file);
+        }
+    }
 
-            tmpBat.deleteOnExit();
+    @Nonnull
+    private static String getVersionStringInternalWmic(@Nonnull File file) throws IOException {
+        File tmpBat = File.createTempFile("getVersionString", "tmp_proxy.bat");
 
-            File tmpOut = File.createTempFile("getVersionString", "tmp_out.txt");
+        tmpBat.deleteOnExit();
 
-            tmpOut.deleteOnExit();
+        File tmpOut = File.createTempFile("getVersionString", "tmp_out.txt");
 
-            String query = "\"%SystemRoot%\\System32\\Wbem\\wmic.exe\""+
-                    " datafile"+
-                    " where"+
-                    String.format(" name=\"%s\"", file.getAbsolutePath().replaceAll("\\\\", "\\\\\\\\"))+
-                    " get"+
-                    " Version"+
-                    " /value"+
-                    String.format(" 1>\"%s\"", tmpOut.getAbsolutePath().replaceAll("\\\\", "\\\\\\\\"));
+        tmpOut.deleteOnExit();
 
-            //System.out.println("load " + query);
+        String query = "\"%SystemRoot%\\System32\\Wbem\\wmic.exe\""+
+                " datafile"+
+                " where"+
+                String.format(" name=\"%s\"", file.getAbsolutePath().replaceAll("\\\\", "\\\\\\\\"))+
+                " get"+
+                " Version"+
+                " /value"+
+                String.format(" 1>\"%s\"", tmpOut.getAbsolutePath().replaceAll("\\\\", "\\\\\\\\"));
 
-            Files.write(tmpBat.toPath(), Arrays.asList("chcp 65001", query, "EXIT /B %ERRORLEVEL%"));
+        //System.out.println("load " + query);
 
-            ProcCaller proc = new ProcCaller(tmpBat.getAbsolutePath());
+        Files.write(tmpBat.toPath(), Arrays.asList("chcp 65001", query, "EXIT /B %ERRORLEVEL%"));
 
-            proc.exec();
+        ProcCaller proc = new ProcCaller(tmpBat.getAbsolutePath());
 
-            if (proc.exitVal() != 0) {
-                throw new IOException(proc.getErrString());
-            }
+        proc.exec();
+
+        if (proc.exitVal() != 0) {
+            throw new IOException(proc.getErrString());
+        }
 
-            BufferedReader reader = new BufferedReader(new InputStreamReader(new FileInputStream(tmpOut), StandardCharsets.UTF_8));
+        StringBuilder sb = new StringBuilder();
+        InputStreamReader inputStream = new InputStreamReader(new FileInputStream(tmpOut), StandardCharsets.UTF_8);
 
-            StringBuilder sb = new StringBuilder();
+        try(BufferedReader reader = new BufferedReader(inputStream)) {
             String line;
 
             while ((line = reader.readLine()) != null) {
                 sb.append(line);
             }
+        };
 
-            String versionString = sb.toString().replaceAll("[^0-9.]", "");
+        String versionString = sb.toString().replaceAll("[^0-9.]", "");
 
-            if (versionString.isEmpty()) versionString = null;
+        if (versionString.isEmpty()) versionString = null;
 
-            if (versionString == null) {
-                throw new IOException(
-                    "Version string "
-                    + sb.toString()
-                    + " from file produced by WMIC wasn't readable. "
-                    + "This is the second failed attempt after dorkbox PE failed with exception.",
-                    e);
-            }
-
-            return versionString;
+        if (versionString == null) {
+            throw new IOException(
+                "Version string "
+                + sb.toString()
+                + " from file produced by WMIC wasn't readable. "
+                + "This is the second failed attempt after dorkbox PE failed with exception."
+            );
         }
+
+        return versionString;
     }
 
     @Nonnull