IDEA-303071 do not download maven common libs if they are already downloaded

GitOrigin-RevId: c4a70dbb8080ad73a5cb6fbcd824da92d05981e8

build/deps/src/org/jetbrains/intellij/build/impl/BundledMavenDownloader.kt

@@ -2,8 +2,11 @@
 package org.jetbrains.intellij.build.impl
 
 import org.jetbrains.intellij.build.dependencies.*
+import java.math.BigInteger
 import java.nio.file.Files
 import java.nio.file.Path
+import java.nio.file.StandardCopyOption
+import java.security.MessageDigest
 
 object BundledMavenDownloader {
   private val mavenCommonLibs: List<String> = listOf(
@@ -26,24 +29,60 @@ object BundledMavenDownloader {
     println("Maven common libs at $commonLibs")
   }
 
+  private fun fileChecksum(path: Path): String? {
+    return try {
+      val md5 = MessageDigest.getInstance("MD5")
+      md5.update(Files.readAllBytes(path))
+      val digest = md5.digest()
+      BigInteger(1, digest).toString(32)
+    }
+    catch (e: Exception) {
+      null
+    }
+  }
+
   fun downloadMavenCommonLibs(communityRoot: BuildDependenciesCommunityRoot): Path {
     val root = communityRoot.communityRoot.resolve("plugins/maven/maven3-server-common/lib")
-    BuildDependenciesUtil.cleanDirectory(root)
+    Files.createDirectories(root)
+    val targetToSourceFiles = HashMap<Path, Path>()
 
     for (coordinates in mavenCommonLibs) {
       val split = coordinates.split(':')
       check(split.size == 3) {
         "Expected exactly 3 coordinates: $coordinates"
       }
-
+      val targetFile = root.resolve("${split[1]}-${split[2]}.jar")
       val uri = BuildDependenciesDownloader.getUriForMavenArtifact(
         BuildDependenciesConstants.MAVEN_CENTRAL_URL,
         split[0], split[1], split[2], "jar"
       )
-
-      val file = BuildDependenciesDownloader.downloadFileToCacheLocation(communityRoot, uri)
-      Files.copy(file, root.resolve("${split[1]}-${split[2]}.jar"))
+      val sourceFile = BuildDependenciesDownloader.downloadFileToCacheLocation(communityRoot, uri)
+      targetToSourceFiles[targetFile] = sourceFile
     }
+
+    Files.list(root).use { stream ->
+      stream.forEach { file: Path? ->
+        run {
+          if (!targetToSourceFiles.containsKey(file)) {
+            BuildDependenciesUtil.deleteFileOrFolder(file)
+          }
+        }
+      }
+    }
+
+    for (targetFile in targetToSourceFiles.keys) {
+      val sourceFile = targetToSourceFiles[targetFile]!!
+      if (!Files.exists(targetFile)) {
+        Files.copy(sourceFile, targetFile)
+      } else {
+        val sourceCheckSum = fileChecksum(sourceFile)
+        val targetCheckSum = fileChecksum(targetFile)
+        if (!sourceCheckSum.equals(targetCheckSum)) {
+          Files.copy(sourceFile, targetFile, StandardCopyOption.REPLACE_EXISTING)
+        }
+      }
+    }
+
     return root
   }
 

platform/build-scripts/downloader/src/org/jetbrains/intellij/build/dependencies/BuildDependenciesUtil.java

@@ -440,17 +440,19 @@ public final class BuildDependenciesUtil {
     return s.substring(start, end);
   }
 
+  public static void deleteFileOrFolder(Path file) {
+    try {
+      MoreFiles.deleteRecursively(file, RecursiveDeleteOption.ALLOW_INSECURE);
+    }
+    catch (IOException e) {
+      throw new RuntimeException(e);
+    }
+  }
+
   public static void cleanDirectory(Path directory) throws IOException {
     Files.createDirectories(directory);
     try (Stream<Path> stream = Files.list(directory)) {
-      stream.forEach(path -> {
-        try {
-          MoreFiles.deleteRecursively(path, RecursiveDeleteOption.ALLOW_INSECURE);
-        }
-        catch (IOException e) {
-          throw new RuntimeException(e);
-        }
-      });
+      stream.forEach(BuildDependenciesUtil::deleteFileOrFolder);
     }
   }