update

x-pack/plugin/esql/qa/testFixtures/src/main/resources/hash.csv-spec

@@ -1,17 +1,13 @@
-md5
+hash
 required_capability: hash_function
 
-ROW value = "test" | EVAL hash = hash("md5", value);
+FROM languages 
+| EVAL md5 = hash("md5", language_name), sha256 = hash("sha256", language_name) 
+| KEEP language_name, md5, sha256;
 
-value:keyword | hash:keyword
-test          | 098f6bcd4621d373cade4e832627b4f6
-;
-
-sha256
-required_capability: hash_function
-
-ROW value = "test" | EVAL hash = hash("sha256", value);
-
-value:keyword | hash:keyword
-test          | 9f86d081884c7d659a2feaa0c55ad015a3bf4f1b2b0b822cd15d6c15b0f00a08
+language_name:keyword | md5:keyword                      | sha256:keyword
+English               | 78463a384a5aa4fad5fa73e2f506ecfc | ba118bf7fc9c1aedc1edb28a0aa86e0b43b681f222af6616e13c43be87815b06
+French                | ad225f707802ba118c22987186dd38e8 | 7458199fe97a184002bfd3c42bae81371f0ae2229b5c0a257a9bae77e4f4eda8
+Spanish               | cb5480c32e71778852b08ae1e8712775 | 3411059cb8e0660e29dd7a3737e65a28b08eb01524a8ebc3d4168932649f23e6
+German                | 86bc3115eb4e9873ac96904a4a68e19e | a659b60d246dce8d4865d45673963de83d0e49a57e8559da98581c2bc5d7d97f
 ;

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/scalar/hash/Hash.java

@@ -13,6 +13,7 @@
 import org.elasticsearch.common.io.stream.StreamOutput;
 import org.elasticsearch.compute.ann.Evaluator;
 import org.elasticsearch.compute.ann.Fixed;
+import org.elasticsearch.compute.operator.BreakingBytesRefBuilder;
 import org.elasticsearch.compute.operator.EvalOperator;
 import org.elasticsearch.xpack.esql.core.expression.Expression;
 import org.elasticsearch.xpack.esql.core.tree.NodeInfo;
@@ -92,32 +93,51 @@ public boolean foldable() {
     }
 
     @Evaluator(warnExceptions = NoSuchAlgorithmException.class)
-    static BytesRef process(BytesRef alg, BytesRef input) throws NoSuchAlgorithmException {
-        return hash(MessageDigest.getInstance(alg.utf8ToString()), input);
+    static BytesRef process(@Fixed(includeInToString = false, build = true) BreakingBytesRefBuilder scratch, BytesRef alg, BytesRef input)
+        throws NoSuchAlgorithmException {
+        return hash(scratch, MessageDigest.getInstance(alg.utf8ToString()), input);
     }
 
     @Evaluator(extraName = "Constant")
-    static BytesRef processConstant(@Fixed(build = true) MessageDigest alg, BytesRef input) {
-        return hash(alg, input);
+    static BytesRef processConstant(
+        @Fixed(includeInToString = false, build = true) BreakingBytesRefBuilder scratch,
+        @Fixed(build = true) MessageDigest alg,
+        BytesRef input
+    ) {
+        return hash(scratch, alg, input);
     }
 
-    private static BytesRef hash(MessageDigest alg, BytesRef input) {
+    private static BytesRef hash(BreakingBytesRefBuilder scratch, MessageDigest alg, BytesRef input) {
+        alg.reset();
         alg.update(input.bytes, input.offset, input.length);
-        var result = alg.digest();
-        return new BytesRef(HexFormat.of().formatHex(result));
+        var digest = alg.digest();
+        scratch.clear();
+        scratch.grow(digest.length * 2);
+        scratch.append(new BytesRef(HexFormat.of().formatHex(digest)));
+        return scratch.bytesRefView();
     }
 
     @Override
     public EvalOperator.ExpressionEvaluator.Factory toEvaluator(ToEvaluator toEvaluator) {
         if (alg.foldable() && alg.dataType() == DataType.KEYWORD) {
             try {
                 var md = MessageDigest.getInstance(((BytesRef) alg.fold()).utf8ToString());
-                return new HashConstantEvaluator.Factory(source(), context -> md, toEvaluator.apply(input));
+                return new HashConstantEvaluator.Factory(
+                    source(),
+                    context -> new BreakingBytesRefBuilder(context.breaker(), "hash"),
+                    context -> md,
+                    toEvaluator.apply(input)
+                );
             } catch (NoSuchAlgorithmException e) {
                 throw new IllegalArgumentException(e);
             }
         } else {
-            return new HashEvaluator.Factory(source(), toEvaluator.apply(alg), toEvaluator.apply(input));
+            return new HashEvaluator.Factory(
+                source(),
+                context -> new BreakingBytesRefBuilder(context.breaker(), "hash"),
+                toEvaluator.apply(alg),
+                toEvaluator.apply(input)
+            );
         }
     }