feat: add native compiled pattern state API

reggie-runtime/src/main/java/com/datadoghq/reggie/ReggieFlags.java

@@ -19,6 +19,7 @@
 public final class ReggieFlags {
   // Keep these separate from java.util.regex.Pattern's values so an accidental JDK flag is never
   // silently interpreted as a different Reggie flag.
+  public static final int NONE = 0;
   public static final int CASE_INSENSITIVE = 1 << 24;
   public static final int MULTILINE = 1 << 25;
   public static final int DOTALL = 1 << 26;

reggie-runtime/src/main/java/com/datadoghq/reggie/runtime/LinearTokenSequenceMatcher.java

@@ -129,6 +129,44 @@ boolean matchIntoBounded(
     return true;
   }
 
+  MatchWorkspace newMatchWorkspace() {
+    return newWorkspace();
+  }
+
+  int groupCount() {
+    return groupCount;
+  }
+
+  int groupIndex(String name) {
+    Objects.requireNonNull(name, "name");
+    Integer index = nameToIndex.get(name);
+    if (index == null) {
+      throw new IllegalArgumentException("unknown group name: " + name);
+    }
+    return index;
+  }
+
+  boolean matchIntoBounded(
+      CharSequence input,
+      int start,
+      int end,
+      int[] groupStarts,
+      int[] groupEnds,
+      MatchWorkspace workspace) {
+    Objects.requireNonNull(input, "input");
+    Objects.requireNonNull(groupStarts, "groupStarts");
+    Objects.requireNonNull(groupEnds, "groupEnds");
+    Objects.requireNonNull(workspace, "workspace");
+    validateRegion(input, start, end);
+    if (groupStarts.length <= groupCount || groupEnds.length <= groupCount) {
+      throw new IndexOutOfBoundsException("group arrays too small for " + groupCount + " groups");
+    }
+    if (!matchesAt(input, start, end, workspace, true)) return false;
+    System.arraycopy(workspace.starts, 0, groupStarts, 0, groupCount + 1);
+    System.arraycopy(workspace.ends, 0, groupEnds, 0, groupCount + 1);
+    return true;
+  }
+
   private MatchResult toMatchResult(String input, MatchWorkspace workspace) {
     if (!nameToIndex.isEmpty()) {
       return new NamedMatchResultImpl(
@@ -479,7 +517,7 @@ private static int maxOptionalDepth(Iterable<LinearTokenSequencePlan.Op> ops) {
     return max;
   }
 
-  private static final class MatchWorkspace {
+  static final class MatchWorkspace {
     final int[] starts;
     final int[] ends;
     final int[][] optionalStarts;

reggie-runtime/src/main/java/com/datadoghq/reggie/runtime/ReggieCompilationRejection.java

@@ -0,0 +1,26 @@
+/*
+ * Copyright 2026-Present Datadog, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.datadoghq.reggie.runtime;
+
+/** Reason the native named linear-token-sequence profile did not admit a request. */
+public enum ReggieCompilationRejection {
+  UNSUPPORTED_FLAGS,
+  SOURCE_INLINE_MODIFIER,
+  PARSE_FAILURE,
+  PLAN_UNAVAILABLE,
+  MISSING_NAMED_CAPTURE,
+  PROFILE_INELIGIBLE
+}

reggie-runtime/src/main/java/com/datadoghq/reggie/runtime/ReggieCompilationResult.java

@@ -0,0 +1,59 @@
+/*
+ * Copyright 2026-Present Datadog, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.datadoghq.reggie.runtime;
+
+import java.util.Objects;
+
+/** Immutable outcome of a native named linear-token-sequence compilation request. */
+public final class ReggieCompilationResult {
+  private final ReggieCompiledPattern pattern;
+  private final ReggieCompilationRejection rejection;
+
+  private ReggieCompilationResult(
+      ReggieCompiledPattern pattern, ReggieCompilationRejection rejection) {
+    if ((pattern == null) == (rejection == null)) {
+      throw new IllegalArgumentException("exactly one of pattern or rejection is required");
+    }
+    this.pattern = pattern;
+    this.rejection = rejection;
+  }
+
+  static ReggieCompilationResult admitted(ReggieCompiledPattern pattern) {
+    return new ReggieCompilationResult(Objects.requireNonNull(pattern, "pattern"), null);
+  }
+
+  static ReggieCompilationResult rejected(ReggieCompilationRejection rejection) {
+    return new ReggieCompilationResult(null, Objects.requireNonNull(rejection, "rejection"));
+  }
+
+  public boolean isAdmitted() {
+    return pattern != null;
+  }
+
+  public ReggieCompiledPattern pattern() {
+    if (pattern == null) {
+      throw new IllegalStateException("compilation was rejected: " + rejection);
+    }
+    return pattern;
+  }
+
+  public ReggieCompilationRejection rejection() {
+    if (rejection == null) {
+      throw new IllegalStateException("compilation was admitted");
+    }
+    return rejection;
+  }
+}

reggie-runtime/src/main/java/com/datadoghq/reggie/runtime/ReggieCompileFlag.java

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2026-Present Datadog, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.datadoghq.reggie.runtime;
+
+import com.datadoghq.reggie.ReggieFlags;
+
+/** Flags supported by the native named linear-token-sequence compilation profile. */
+public enum ReggieCompileFlag {
+  NONE(ReggieFlags.NONE),
+  DOTALL(ReggieFlags.DOTALL);
+
+  private final int reggieFlags;
+
+  ReggieCompileFlag(int reggieFlags) {
+    this.reggieFlags = reggieFlags;
+  }
+
+  int reggieFlags() {
+    return reggieFlags;
+  }
+}

reggie-runtime/src/main/java/com/datadoghq/reggie/runtime/ReggieCompileRequest.java

@@ -0,0 +1,26 @@
+/*
+ * Copyright 2026-Present Datadog, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.datadoghq.reggie.runtime;
+
+import java.util.Objects;
+
+/** Immutable request for the native named linear-token-sequence compilation profile. */
+public record ReggieCompileRequest(String source, ReggieCompileFlag flag) {
+  public ReggieCompileRequest {
+    Objects.requireNonNull(source, "source");
+    Objects.requireNonNull(flag, "flag");
+  }
+}

reggie-runtime/src/main/java/com/datadoghq/reggie/runtime/ReggieCompiledPattern.java

@@ -0,0 +1,51 @@
+/*
+ * Copyright 2026-Present Datadog, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.datadoghq.reggie.runtime;
+
+import java.util.Objects;
+
+/**
+ * Immutable native compiled pattern for the named linear-token-sequence profile.
+ *
+ * <p>This API never selects another Reggie strategy and never delegates to the JDK.
+ */
+public final class ReggieCompiledPattern {
+  private final LinearTokenSequenceMatcher matcher;
+
+  private ReggieCompiledPattern(LinearTokenSequenceMatcher matcher) {
+    this.matcher = Objects.requireNonNull(matcher, "matcher");
+  }
+
+  /**
+   * Attempts native compilation without consulting the general compiler or either compiler cache.
+   */
+  public static ReggieCompilationResult tryCompile(ReggieCompileRequest request) {
+    Objects.requireNonNull(request, "request");
+    RuntimeCompiler.NamedOnlyLtsCompilation compilation =
+        RuntimeCompiler.tryCompileNamedOnlyLinearTokenSequence(
+            request.source(), request.flag().reggieFlags());
+    if (compilation.matcher() != null) {
+      return ReggieCompilationResult.admitted(new ReggieCompiledPattern(compilation.matcher()));
+    }
+    return ReggieCompilationResult.rejected(
+        ReggieCompilationRejection.valueOf(compilation.rejection().name()));
+  }
+
+  /** Creates a new single-thread-confined state object for matching this immutable pattern. */
+  public ReggieMatchState newState() {
+    return new ReggieMatchState(matcher);
+  }
+}

reggie-runtime/src/main/java/com/datadoghq/reggie/runtime/ReggieMatchState.java

@@ -0,0 +1,82 @@
+/*
+ * Copyright 2026-Present Datadog, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.datadoghq.reggie.runtime;
+
+import java.util.Arrays;
+import java.util.Objects;
+
+/**
+ * Single-thread-confined mutable matching state for a {@link ReggieCompiledPattern}.
+ *
+ * <p>The state retains spans only; it never retains the input sequence.
+ */
+public final class ReggieMatchState {
+  private final LinearTokenSequenceMatcher matcher;
+  private final LinearTokenSequenceMatcher.MatchWorkspace workspace;
+  private final int[] starts;
+  private final int[] ends;
+  private boolean matched;
+
+  ReggieMatchState(LinearTokenSequenceMatcher matcher) {
+    this.matcher = Objects.requireNonNull(matcher, "matcher");
+    this.workspace = matcher.newMatchWorkspace();
+    this.starts = new int[matcher.groupCount() + 1];
+    this.ends = new int[matcher.groupCount() + 1];
+    clear();
+  }
+
+  /**
+   * Attempts a full match inside {@code [start, end)}.
+   *
+   * <p>Prior state is cleared before validating the input or attempting the match.
+   */
+  public boolean matches(CharSequence input, int start, int end) {
+    clear();
+    return matched = matcher.matchIntoBounded(input, start, end, starts, ends, workspace);
+  }
+
+  public int start() {
+    requireMatched();
+    return starts[0];
+  }
+
+  public int end() {
+    requireMatched();
+    return ends[0];
+  }
+
+  public int start(String name) {
+    requireMatched();
+    return starts[matcher.groupIndex(name)];
+  }
+
+  public int end(String name) {
+    requireMatched();
+    return ends[matcher.groupIndex(name)];
+  }
+
+  private void clear() {
+    Arrays.fill(starts, -1);
+    Arrays.fill(ends, -1);
+    matched = false;
+  }
+
+  private void requireMatched() {
+    if (!matched) {
+      throw new IllegalStateException("there is no current match");
+    }
+  }
+}