From 86338266807cb8d78082179733b31a8fd0be972c Mon Sep 17 00:00:00 2001
From: Liam Miller-Cushon <cushon@google.com>
Date: Fri, 4 Apr 2025 14:10:48 -0700
Subject: [PATCH] Optimize string wrapping

PiperOrigin-RevId: 744065507
---
 .../googlejavaformat/java/StringWrapper.java  | 36 ++++++----
 .../java/StringWrapperIntegrationTest.java    | 65 +++++++++++++++++++
 2 files changed, 89 insertions(+), 12 deletions(-)

diff --git a/core/src/main/java/com/google/googlejavaformat/java/StringWrapper.java b/core/src/main/java/com/google/googlejavaformat/java/StringWrapper.java
index 27450d82f..f1014e52f 100644
--- a/core/src/main/java/com/google/googlejavaformat/java/StringWrapper.java
+++ b/core/src/main/java/com/google/googlejavaformat/java/StringWrapper.java
@@ -53,7 +53,6 @@
 import java.util.List;
 import java.util.Map;
 import java.util.concurrent.atomic.AtomicBoolean;
-import java.util.stream.Stream;
 import javax.tools.Diagnostic;
 import javax.tools.DiagnosticCollector;
 import javax.tools.DiagnosticListener;
@@ -316,19 +315,21 @@ private static ImmutableList<String> stringComponents(
   }
 
   static int hasEscapedWhitespaceAt(String input, int idx) {
-    return Stream.of("\\t")
-        .mapToInt(x -> input.startsWith(x, idx) ? x.length() : -1)
-        .filter(x -> x != -1)
-        .findFirst()
-        .orElse(-1);
+    if (input.startsWith("\\t", idx)) {
+      return 2;
+    }
+    return -1;
   }
 
   static int hasEscapedNewlineAt(String input, int idx) {
-    return Stream.of("\\r\\n", "\\r", "\\n")
-        .mapToInt(x -> input.startsWith(x, idx) ? x.length() : -1)
-        .filter(x -> x != -1)
-        .findFirst()
-        .orElse(-1);
+    int offset = 0;
+    if (input.startsWith("\\r", idx)) {
+      offset += 2;
+    }
+    if (input.startsWith("\\n", idx)) {
+      offset += 2;
+    }
+    return offset > 0 ? offset : -1;
   }
 
   /**
@@ -360,7 +361,7 @@ private static String reflow(
       List<String> line = new ArrayList<>();
       // If we know this is going to be the last line, then remove a bit of width to account for the
       // trailing characters.
-      if (input.stream().mapToInt(String::length).sum() <= width) {
+      if (totalLengthLessThanOrEqual(input, width)) {
         // This isn’t quite optimal, but arguably good enough. See b/179561701
         width -= trailing;
       }
@@ -391,6 +392,17 @@ private static String reflow(
                 "\""));
   }
 
+  private static boolean totalLengthLessThanOrEqual(Iterable<String> input, int length) {
+    int total = 0;
+    for (String s : input) {
+      total += s.length();
+      if (total > length) {
+        return false;
+      }
+    }
+    return true;
+  }
+
   /**
    * Flattens the given binary expression tree, and extracts the subset that contains the given path
    * and any adjacent nodes that are also string literals.
diff --git a/core/src/test/java/com/google/googlejavaformat/java/StringWrapperIntegrationTest.java b/core/src/test/java/com/google/googlejavaformat/java/StringWrapperIntegrationTest.java
index 53fb54d91..5032ac97c 100644
--- a/core/src/test/java/com/google/googlejavaformat/java/StringWrapperIntegrationTest.java
+++ b/core/src/test/java/com/google/googlejavaformat/java/StringWrapperIntegrationTest.java
@@ -365,6 +365,71 @@ public static Collection<Object[]> parameters() {
           "}"
         },
       },
+      {
+        {
+          "class T {", //
+          "  String s = \"\\r\\rone\\rlong\\rincredibly\\runbroken\\rsentence\\rmoving\\rfrom\\r"
+              + " topic\\rto\\r topic\\rso\\rthat\\rno-one\\rhad\\ra\\rchance\\rto\\rinterrupt\";",
+          "}"
+        },
+        {
+          "class T {",
+          "  String s =",
+          "      \"\\r\\r\"",
+          "          + \"one\\r\"",
+          "          + \"long\\r\"",
+          "          + \"incredibly\\r\"",
+          "          + \"unbroken\\r\"",
+          "          + \"sentence\\r\"",
+          "          + \"moving\\r\"",
+          "          + \"from\\r\"",
+          "          + \" topic\\r\"",
+          "          + \"to\\r\"",
+          "          + \" topic\\r\"",
+          "          + \"so\\r\"",
+          "          + \"that\\r\"",
+          "          + \"no-one\\r\"",
+          "          + \"had\\r\"",
+          "          + \"a\\r\"",
+          "          + \"chance\\r\"",
+          "          + \"to\\r\"",
+          "          + \"interrupt\";",
+          "}",
+        },
+      },
+      {
+        {
+          "class T {", //
+          "  String s = \"\\r\\n\\r\\none\\r\\nlong\\r\\nincredibly\\r\\nunbroken\\r\\nsentence"
+              + "\\r\\nmoving\\r\\nfrom\\r\\n topic\\r\\nto\\r\\n topic\\r\\nso\\r\\nthat\\r\\n"
+              + "no-one\\r\\nhad\\r\\na\\r\\nchance\\r\\nto\\r\\ninterrupt\";",
+          "}"
+        },
+        {
+          "class T {",
+          "  String s =",
+          "      \"\\r\\n\\r\\n\"",
+          "          + \"one\\r\\n\"",
+          "          + \"long\\r\\n\"",
+          "          + \"incredibly\\r\\n\"",
+          "          + \"unbroken\\r\\n\"",
+          "          + \"sentence\\r\\n\"",
+          "          + \"moving\\r\\n\"",
+          "          + \"from\\r\\n\"",
+          "          + \" topic\\r\\n\"",
+          "          + \"to\\r\\n\"",
+          "          + \" topic\\r\\n\"",
+          "          + \"so\\r\\n\"",
+          "          + \"that\\r\\n\"",
+          "          + \"no-one\\r\\n\"",
+          "          + \"had\\r\\n\"",
+          "          + \"a\\r\\n\"",
+          "          + \"chance\\r\\n\"",
+          "          + \"to\\r\\n\"",
+          "          + \"interrupt\";",
+          "}",
+        },
+      },
     };
     return Arrays.stream(inputsAndOutputs)
         .map(