impl/src/test/java/jakarta/faces/component/UIRepeatBenchmark.java - myfaces - Git at Google

 /*
  * Licensed to the Apache Software Foundation (ASF) under one
  * or more contributor license agreements.  See the NOTICE file
  * distributed with this work for additional information
  * regarding copyright ownership.  The ASF licenses this file
  * to you 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 jakarta.faces.component;

 import org.apache.myfaces.core.api.shared.EditableValueHolderState;

 import java.util.Arrays;

 /**
  * Microbenchmark for the UIRepeat per-row state-save/restore cycle and the full
  * JSF lifecycle phases (APPLY_REQUEST_VALUES, PROCESS_VALIDATIONS, UPDATE_MODEL_VALUES).
  *
  * <p>Run as a plain {@code main()} — no JMH, no test framework needed.
  * To compare before/after the TransientStateHelper change:
  * <ol>
  *   <li>Run with current code (after the change).</li>
  *   <li>{@code git stash} to revert to StateHelper-based code.</li>
  *   <li>Run again and compare.</li>
  * </ol>
  *
  * <p>No FacesContext is required: all benchmarked paths operate purely on
  * in-memory fields and do not call {@code _component.getFacesContext()}.
  *
  * <p>Scenarios exercised:
  * <ul>
  *   <li><b>getter/setter hot path</b> – {@code setValid/isValid},
  *       {@code setSubmittedValue/getSubmittedValue},
  *       {@code setLocalValueSet/isLocalValueSet}.</li>
  *   <li><b>{@code saveTransientState}/{@code restoreTransientState}</b> –
  *       UIRepeat's {@code _rowTransientStates} path.</li>
  *   <li><b>{@code EditableValueHolderState} roundtrip</b> –
  *       UIRepeat's {@code _rowStates} (EVH) path.</li>
  *   <li><b>Full row-switch (render)</b> – EVH save+restore per row, read-only.</li>
  *   <li><b>APPLY_REQUEST_VALUES</b> – restore → decode (setSubmittedValue) → save.</li>
  *   <li><b>PROCESS_VALIDATIONS success</b> – restore → validate OK (setValue + clear sv) → save.</li>
  *   <li><b>PROCESS_VALIDATIONS failure</b> – restore → validate fail (setValid(false)) → save.</li>
  *   <li><b>UPDATE_MODEL_VALUES</b> – restore → updateModel (setValue(null)) → save.</li>
  * </ul>
  */
 public class UIRepeatBenchmark
 {
     static final int ROWS    =       10;
     static final int WARMUP  =  300_000;
     static final int MEASURE =  3_000_000;
     static final int ROUNDS  =       12;

     /** Pre-allocated submitted-value strings — avoids String allocation inside benchmarked loops. */
     static final String[] SUBMITTED_VALUES = new String[ROWS];
     static
     {
         for (int i = 0; i < ROWS; i++)
         {
             SUBMITTED_VALUES[i] = "field-value-" + i;
         }
     }

     // ── runner ────────────────────────────────────────────────────────────────

     static double run(String label, Runnable bench)
     {
         for (int i = 0; i < WARMUP; i++)
         {
             bench.run();
         }
         long[] times = new long[ROUNDS];
         for (int r = 0; r < ROUNDS; r++)
         {
             long t0 = System.nanoTime();
             for (int i = 0; i < MEASURE; i++)
             {
                 bench.run();
             }
             times[r] = System.nanoTime() - t0;
         }
         Arrays.sort(times);
         double ns = (double) times[ROUNDS / 2] / MEASURE;
         System.out.printf("  %-50s %6.2f ns/op%n", label, ns);
         return ns;
     }

     static void header(String title)
     {
         System.out.println("\n=== " + title + " ===");
     }

     // ── helpers ───────────────────────────────────────────────────────────────

     /** Reset component back to all-default state between sub-benchmarks. */
     static void resetInput(UIInput input)
     {
         input.setValid(true);
         input.setLocalValueSet(false);
         input.setSubmittedValue(null);
     }

     /**
      * Pre-populate N per-row snapshots that simulate a realistic mix:
      * some rows are clean (all defaults), others have validation errors.
      */
     static Object[] buildTransientSnapshots(UIInput input, int n)
     {
         Object[] snaps = new Object[n];
         for (int i = 0; i < n; i++)
         {
             if (i % 3 == 0)
             {
                 // row has a validation error
                 input.setValid(false);
                 input.setSubmittedValue("bad-value-" + i);
                 input.setLocalValueSet(false);
             }
             else
             {
                 // row is clean
                 input.setValid(true);
                 input.setSubmittedValue(null);
                 input.setLocalValueSet(false);
             }
             snaps[i] = input.saveTransientState(null);
         }
         resetInput(input);
         return snaps;
     }

     static EditableValueHolderState[] buildEvhSnapshots(UIInput input, int n)
     {
         EditableValueHolderState[] snaps = new EditableValueHolderState[n];
         for (int i = 0; i < n; i++)
         {
             if (i % 3 == 0)
             {
                 input.setValid(false);
                 input.setSubmittedValue("bad-value-" + i);
             }
             else
             {
                 input.setValid(true);
                 input.setSubmittedValue(null);
             }
             snaps[i] = EditableValueHolderState.create(input);
         }
         resetInput(input);
         return snaps;
     }

     // ── main ──────────────────────────────────────────────────────────────────

     public static void main(String[] args)
     {
         UIInput input = new UIInput();

         // ── 1. getter / setter hot path ───────────────────────────────────────
         header("getter/setter hot path  (non-default state, matches validate() path)");

         run("setValid(false) + isValid()", () ->
         {
             input.setValid(false);
             boolean v = input.isValid();
         });

         run("setValid(true) + isValid()  [default, no-op path]", () ->
         {
             input.setValid(true);
             boolean v = input.isValid();
         });

         run("setSubmittedValue(str) + getSubmittedValue()", () ->
         {
             input.setSubmittedValue("hello");
             Object sv = input.getSubmittedValue();
         });

         run("setSubmittedValue(null) + getSubmittedValue() [clear path]", () ->
         {
             input.setSubmittedValue(null);
             Object sv = input.getSubmittedValue();
         });

         run("setLocalValueSet(true) + isLocalValueSet()", () ->
         {
             input.setLocalValueSet(true);
             boolean lv = input.isLocalValueSet();
         });

         run("all three setters + getters combined", () ->
         {
             input.setValid(false);
             input.setSubmittedValue("v");
             input.setLocalValueSet(false);
             boolean v = input.isValid();
             Object sv = input.getSubmittedValue();
             boolean lv = input.isLocalValueSet();
         });

         // ── 2. saveTransientState + restoreTransientState ─────────────────────
         // This is UIRepeat's _rowTransientStates path: one save+restore per
         // child component per row switch.
         header("saveTransientState + restoreTransientState  (UIRepeat _rowTransientStates path)");

         // clean state (null snapshot — the common case for valid, unsubmitted rows)
         resetInput(input);
         run("save+restore  [all defaults — null snapshot]", () ->
         {
             Object s = input.saveTransientState(null);
             input.restoreTransientState(null, s);
         });

         // dirty state (validation error — non-null snapshot)
         input.setValid(false);
         input.setSubmittedValue("bad");
         run("save+restore  [valid=false, submittedValue set]", () ->
         {
             Object s = input.saveTransientState(null);
             input.restoreTransientState(null, s);
         });
         resetInput(input);

         // ── 3. EditableValueHolderState roundtrip ─────────────────────────────
         // This is UIRepeat's _rowStates (EVH) path: UIRepeat calls
         // EditableValueHolderState.create(evh) when leaving a row and
         // state.restoreState(evh) when entering the next row.
         header("EditableValueHolderState roundtrip  (UIRepeat _rowStates path)");

         // clean row — create() returns null, EMPTY.restoreState() is used
         resetInput(input);
         run("create [defaults → null] + EMPTY.restoreState", () ->
         {
             EditableValueHolderState s = EditableValueHolderState.create(input);
             // s is null for default state; UIRepeat uses EMPTY.restoreState
             EditableValueHolderState.EMPTY.restoreState(input);
         });

         // dirty row — create() allocates a new object
         input.setValid(false);
         input.setSubmittedValue("bad-value");
         run("create [non-default] + restoreState", () ->
         {
             EditableValueHolderState s = EditableValueHolderState.create(input);
             s.restoreState(input);
         });
         resetInput(input);

         // ── 4a. Full iteration — MODERN path ─────────────────────────────────
         // _setIndexWithoutPreserveComponentState: only EditableValueHolderState,
         // NO saveTransientState/restoreTransientState on children.
         // This is the path taken by virtually all real UIRepeat usage.
         header("Full row-switch — MODERN path  (" + ROWS + " rows, EVH only)");

         EditableValueHolderState[] evhSnaps = buildEvhSnapshots(input, ROWS);

         run("full iteration  (EVH save+restore per row only)", () ->
         {
             for (int row = 0; row < ROWS; row++)
             {
                 // --- UIRepeat: entering row (restoreChildStates) ---
                 EditableValueHolderState evh = evhSnaps[row];
                 if (evh != null)
                 {
                     evh.restoreState(input);
                 }
                 else
                 {
                     EditableValueHolderState.EMPTY.restoreState(input);
                 }

                 // --- (validation / rendering would happen here) ---
                 boolean valid = input.isValid();
                 Object sv = input.getSubmittedValue();

                 // --- UIRepeat: leaving row (saveChildStates) ---
                 evhSnaps[row] = EditableValueHolderState.create(input);
             }
         });

         // ── 4b. Full iteration — LEGACY path ──────────────────────────────────
         // _setIndexWithPreserveComponentState: only _rowTransientStates via
         // saveTransientState/restoreTransientState on children.
         // Only active when rowStatePreserved=true.
         header("Full row-switch — LEGACY path  (" + ROWS + " rows, transient only)");

         Object[] transientSnaps = buildTransientSnapshots(input, ROWS);

         run("full iteration  (transient save+restore per row only)", () ->
         {
             for (int row = 0; row < ROWS; row++)
             {
                 // --- UIRepeat: entering row (restoreTransientDescendantComponentStates) ---
                 input.restoreTransientState(null, transientSnaps[row]);

                 // --- (validation / rendering would happen here) ---
                 boolean valid = input.isValid();
                 Object sv = input.getSubmittedValue();

                 // --- UIRepeat: leaving row (saveTransientDescendantComponentStates) ---
                 transientSnaps[row] = input.saveTransientState(null);
             }
         });

         // ── 5a. APPLY_REQUEST_VALUES ───────────────────────────────────────────
         // Simulates UIRepeat.processDecodes(): for each row, restore EVH state,
         // let the renderer decode the request (setSubmittedValue), then save EVH state.
         // This is where Mojarra's plain-field submittedValue has a structural advantage:
         // its setSubmittedValue is a direct field write; ours goes through TransientStateHelper.
         header("Full row-switch — APPLY_REQUEST_VALUES  (" + ROWS + " rows)");

         // Start with empty snapshots (fresh request, no prior per-row state).
         EditableValueHolderState[] applySnaps = new EditableValueHolderState[ROWS];
         resetInput(input);

         run("restore → decode (setSubmittedValue) → save", () ->
         {
             for (int row = 0; row < ROWS; row++)
             {
                 // UIRepeat: entering row — restore previous EVH state (null on first visit)
                 EditableValueHolderState prevEvh = applySnaps[row];
                 if (prevEvh != null)
                 {
                     prevEvh.restoreState(input);
                 }
                 else
                 {
                     EditableValueHolderState.EMPTY.restoreState(input);
                 }

                 // Simulate renderer decode: sets the submitted form value on the component
                 input.setSubmittedValue(SUBMITTED_VALUES[row]);

                 // UIRepeat: leaving row — save updated EVH state
                 applySnaps[row] = EditableValueHolderState.create(input);
             }
         });

         // ── 5b. PROCESS_VALIDATIONS — success ─────────────────────────────────
         // Simulates UIInput.validate() succeeding: reads submittedValue, converts it,
         // calls setValue(convertedValue) [which also sets localValueSet=true],
         // then clears submittedValue.
         header("Full row-switch — PROCESS_VALIDATIONS success  (" + ROWS + " rows)");

         // Seed snapshots as if APPLY_REQUEST_VALUES already ran: each row has a submittedValue.
         EditableValueHolderState[] validateOkSnaps = new EditableValueHolderState[ROWS];
         for (int i = 0; i < ROWS; i++)
         {
             input.setSubmittedValue(SUBMITTED_VALUES[i]);
             validateOkSnaps[i] = EditableValueHolderState.create(input);
         }
         resetInput(input);

         run("restore → validate OK (setValue + clear sv) → save", () ->
         {
             for (int row = 0; row < ROWS; row++)
             {
                 EditableValueHolderState evh = validateOkSnaps[row];
                 if (evh != null)
                 {
                     evh.restoreState(input);
                 }
                 else
                 {
                     EditableValueHolderState.EMPTY.restoreState(input);
                 }

                 // Simulate UIInput.validate() success path:
                 //   converted = getConvertedValue(...) → skipped (no FacesContext needed)
                 Object sv = input.getSubmittedValue();   // read submitted value
                 input.setValue(sv);                       // store as local value (also sets localValueSet=true)
                 input.setSubmittedValue(null);            // clear submitted value after successful conversion

                 validateOkSnaps[row] = EditableValueHolderState.create(input);
             }
         });

         // ── 5c. PROCESS_VALIDATIONS — failure ─────────────────────────────────
         // Simulates UIInput.validate() failing: reads submittedValue, marks invalid,
         // keeps submittedValue for re-display in the error state.
         header("Full row-switch — PROCESS_VALIDATIONS failure  (" + ROWS + " rows)");

         // Seed snapshots with submitted values.
         EditableValueHolderState[] validateFailSnaps = new EditableValueHolderState[ROWS];
         for (int i = 0; i < ROWS; i++)
         {
             input.setSubmittedValue(SUBMITTED_VALUES[i]);
             validateFailSnaps[i] = EditableValueHolderState.create(input);
         }
         resetInput(input);

         run("restore → validate fail (setValid(false)) → save", () ->
         {
             for (int row = 0; row < ROWS; row++)
             {
                 EditableValueHolderState evh = validateFailSnaps[row];
                 if (evh != null)
                 {
                     evh.restoreState(input);
                 }
                 else
                 {
                     EditableValueHolderState.EMPTY.restoreState(input);
                 }

                 // Simulate UIInput.validate() failure path:
                 //   submittedValue is retained; component is marked invalid
                 Object sv = input.getSubmittedValue();   // read (retained for error display)
                 input.setValid(false);                    // mark invalid

                 validateFailSnaps[row] = EditableValueHolderState.create(input);
             }
         });

         // ── 5d. UPDATE_MODEL_VALUES ────────────────────────────────────────────
         // Simulates UIInput.updateModel() succeeding: checks isValid + isLocalValueSet,
         // writes to EL model (skipped here), then resets the local value.
         // The reset path (setValue(null) + setLocalValueSet(false)) is the hot path
         // because setValue(null) internally also calls setLocalValueSet(true),
         // causing an add-then-remove cycle in TransientStateHelper.
         header("Full row-switch — UPDATE_MODEL_VALUES  (" + ROWS + " rows)");

         // Seed snapshots as if PROCESS_VALIDATIONS success ran: each row has a local value.
         EditableValueHolderState[] updateSnaps = new EditableValueHolderState[ROWS];
         for (int i = 0; i < ROWS; i++)
         {
             input.setValue(SUBMITTED_VALUES[i]);  // also sets localValueSet=true
             updateSnaps[i] = EditableValueHolderState.create(input);
         }
         resetInput(input);

         run("restore → updateModel (setValue(null) + setLocalValueSet(false)) → save", () ->
         {
             for (int row = 0; row < ROWS; row++)
             {
                 EditableValueHolderState evh = updateSnaps[row];
                 if (evh != null)
                 {
                     evh.restoreState(input);
                 }
                 else
                 {
                     EditableValueHolderState.EMPTY.restoreState(input);
                 }

                 // Simulate UIInput.updateModel() success path:
                 if (input.isValid() && input.isLocalValueSet())
                 {
                     // expression.setValue(context.getELContext(), getLocalValue()) skipped
                     input.setValue(null);
                     input.setLocalValueSet(false);
                 }

                 updateSnaps[row] = EditableValueHolderState.create(input);
             }
         });

         System.out.println();
     }
 }
	/*
	* Licensed to the Apache Software Foundation (ASF) under one
	* or more contributor license agreements. See the NOTICE file
	* distributed with this work for additional information
	* regarding copyright ownership. The ASF licenses this file
	* to you 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 jakarta.faces.component;

	import org.apache.myfaces.core.api.shared.EditableValueHolderState;

	import java.util.Arrays;

	/**
	* Microbenchmark for the UIRepeat per-row state-save/restore cycle and the full
	* JSF lifecycle phases (APPLY_REQUEST_VALUES, PROCESS_VALIDATIONS, UPDATE_MODEL_VALUES).
	*
	* <p>Run as a plain {@code main()} — no JMH, no test framework needed.
	* To compare before/after the TransientStateHelper change:
	* <ol>
	* <li>Run with current code (after the change).</li>
	* <li>{@code git stash} to revert to StateHelper-based code.</li>
	* <li>Run again and compare.</li>
	* </ol>
	*
	* <p>No FacesContext is required: all benchmarked paths operate purely on
	* in-memory fields and do not call {@code _component.getFacesContext()}.
	*
	* <p>Scenarios exercised:
	* <ul>
	* <li><b>getter/setter hot path</b> – {@code setValid/isValid},
	* {@code setSubmittedValue/getSubmittedValue},
	* {@code setLocalValueSet/isLocalValueSet}.</li>
	* <li><b>{@code saveTransientState}/{@code restoreTransientState}</b> –
	* UIRepeat's {@code _rowTransientStates} path.</li>
	* <li><b>{@code EditableValueHolderState} roundtrip</b> –
	* UIRepeat's {@code _rowStates} (EVH) path.</li>
	* <li><b>Full row-switch (render)</b> – EVH save+restore per row, read-only.</li>
	* <li><b>APPLY_REQUEST_VALUES</b> – restore → decode (setSubmittedValue) → save.</li>
	* <li><b>PROCESS_VALIDATIONS success</b> – restore → validate OK (setValue + clear sv) → save.</li>
	* <li><b>PROCESS_VALIDATIONS failure</b> – restore → validate fail (setValid(false)) → save.</li>
	* <li><b>UPDATE_MODEL_VALUES</b> – restore → updateModel (setValue(null)) → save.</li>
	* </ul>
	*/
	public class UIRepeatBenchmark
	{
	static final int ROWS = 10;
	static final int WARMUP = 300_000;
	static final int MEASURE = 3_000_000;
	static final int ROUNDS = 12;

	/** Pre-allocated submitted-value strings — avoids String allocation inside benchmarked loops. */
	static final String[] SUBMITTED_VALUES = new String[ROWS];
	static
	{
	for (int i = 0; i < ROWS; i++)
	{
	SUBMITTED_VALUES[i] = "field-value-" + i;
	}
	}

	// ── runner ────────────────────────────────────────────────────────────────

	static double run(String label, Runnable bench)
	{
	for (int i = 0; i < WARMUP; i++)
	{
	bench.run();
	}
	long[] times = new long[ROUNDS];
	for (int r = 0; r < ROUNDS; r++)
	{
	long t0 = System.nanoTime();
	for (int i = 0; i < MEASURE; i++)
	{
	bench.run();
	}
	times[r] = System.nanoTime() - t0;
	}
	Arrays.sort(times);
	double ns = (double) times[ROUNDS / 2] / MEASURE;
	System.out.printf(" %-50s %6.2f ns/op%n", label, ns);
	return ns;
	}

	static void header(String title)
	{
	System.out.println("\n=== " + title + " ===");
	}

	// ── helpers ───────────────────────────────────────────────────────────────

	/** Reset component back to all-default state between sub-benchmarks. */
	static void resetInput(UIInput input)
	{
	input.setValid(true);
	input.setLocalValueSet(false);
	input.setSubmittedValue(null);
	}

	/**
	* Pre-populate N per-row snapshots that simulate a realistic mix:
	* some rows are clean (all defaults), others have validation errors.
	*/
	static Object[] buildTransientSnapshots(UIInput input, int n)
	{
	Object[] snaps = new Object[n];
	for (int i = 0; i < n; i++)
	{
	if (i % 3 == 0)
	{
	// row has a validation error
	input.setValid(false);
	input.setSubmittedValue("bad-value-" + i);
	input.setLocalValueSet(false);
	}
	else
	{
	// row is clean
	input.setValid(true);
	input.setSubmittedValue(null);
	input.setLocalValueSet(false);
	}
	snaps[i] = input.saveTransientState(null);
	}
	resetInput(input);
	return snaps;
	}

	static EditableValueHolderState[] buildEvhSnapshots(UIInput input, int n)
	{
	EditableValueHolderState[] snaps = new EditableValueHolderState[n];
	for (int i = 0; i < n; i++)
	{
	if (i % 3 == 0)
	{
	input.setValid(false);
	input.setSubmittedValue("bad-value-" + i);
	}
	else
	{
	input.setValid(true);
	input.setSubmittedValue(null);
	}
	snaps[i] = EditableValueHolderState.create(input);
	}
	resetInput(input);
	return snaps;
	}

	// ── main ──────────────────────────────────────────────────────────────────

	public static void main(String[] args)
	{
	UIInput input = new UIInput();

	// ── 1. getter / setter hot path ───────────────────────────────────────
	header("getter/setter hot path (non-default state, matches validate() path)");

	run("setValid(false) + isValid()", () ->
	{
	input.setValid(false);
	boolean v = input.isValid();
	});

	run("setValid(true) + isValid() [default, no-op path]", () ->
	{
	input.setValid(true);
	boolean v = input.isValid();
	});

	run("setSubmittedValue(str) + getSubmittedValue()", () ->
	{
	input.setSubmittedValue("hello");
	Object sv = input.getSubmittedValue();
	});

	run("setSubmittedValue(null) + getSubmittedValue() [clear path]", () ->
	{
	input.setSubmittedValue(null);
	Object sv = input.getSubmittedValue();
	});

	run("setLocalValueSet(true) + isLocalValueSet()", () ->
	{
	input.setLocalValueSet(true);
	boolean lv = input.isLocalValueSet();
	});

	run("all three setters + getters combined", () ->
	{
	input.setValid(false);
	input.setSubmittedValue("v");
	input.setLocalValueSet(false);
	boolean v = input.isValid();
	Object sv = input.getSubmittedValue();
	boolean lv = input.isLocalValueSet();
	});

	// ── 2. saveTransientState + restoreTransientState ─────────────────────
	// This is UIRepeat's _rowTransientStates path: one save+restore per
	// child component per row switch.
	header("saveTransientState + restoreTransientState (UIRepeat _rowTransientStates path)");

	// clean state (null snapshot — the common case for valid, unsubmitted rows)
	resetInput(input);
	run("save+restore [all defaults — null snapshot]", () ->
	{
	Object s = input.saveTransientState(null);
	input.restoreTransientState(null, s);
	});

	// dirty state (validation error — non-null snapshot)
	input.setValid(false);
	input.setSubmittedValue("bad");
	run("save+restore [valid=false, submittedValue set]", () ->
	{
	Object s = input.saveTransientState(null);
	input.restoreTransientState(null, s);
	});
	resetInput(input);

	// ── 3. EditableValueHolderState roundtrip ─────────────────────────────
	// This is UIRepeat's _rowStates (EVH) path: UIRepeat calls
	// EditableValueHolderState.create(evh) when leaving a row and
	// state.restoreState(evh) when entering the next row.
	header("EditableValueHolderState roundtrip (UIRepeat _rowStates path)");

	// clean row — create() returns null, EMPTY.restoreState() is used
	resetInput(input);
	run("create [defaults → null] + EMPTY.restoreState", () ->
	{
	EditableValueHolderState s = EditableValueHolderState.create(input);
	// s is null for default state; UIRepeat uses EMPTY.restoreState
	EditableValueHolderState.EMPTY.restoreState(input);
	});

	// dirty row — create() allocates a new object
	input.setValid(false);
	input.setSubmittedValue("bad-value");
	run("create [non-default] + restoreState", () ->
	{
	EditableValueHolderState s = EditableValueHolderState.create(input);
	s.restoreState(input);
	});
	resetInput(input);

	// ── 4a. Full iteration — MODERN path ─────────────────────────────────
	// _setIndexWithoutPreserveComponentState: only EditableValueHolderState,
	// NO saveTransientState/restoreTransientState on children.
	// This is the path taken by virtually all real UIRepeat usage.
	header("Full row-switch — MODERN path (" + ROWS + " rows, EVH only)");

	EditableValueHolderState[] evhSnaps = buildEvhSnapshots(input, ROWS);

	run("full iteration (EVH save+restore per row only)", () ->
	{
	for (int row = 0; row < ROWS; row++)
	{
	// --- UIRepeat: entering row (restoreChildStates) ---
	EditableValueHolderState evh = evhSnaps[row];
	if (evh != null)
	{
	evh.restoreState(input);
	}
	else
	{
	EditableValueHolderState.EMPTY.restoreState(input);
	}

	// --- (validation / rendering would happen here) ---
	boolean valid = input.isValid();
	Object sv = input.getSubmittedValue();

	// --- UIRepeat: leaving row (saveChildStates) ---
	evhSnaps[row] = EditableValueHolderState.create(input);
	}
	});

	// ── 4b. Full iteration — LEGACY path ──────────────────────────────────
	// _setIndexWithPreserveComponentState: only _rowTransientStates via
	// saveTransientState/restoreTransientState on children.
	// Only active when rowStatePreserved=true.
	header("Full row-switch — LEGACY path (" + ROWS + " rows, transient only)");

	Object[] transientSnaps = buildTransientSnapshots(input, ROWS);

	run("full iteration (transient save+restore per row only)", () ->
	{
	for (int row = 0; row < ROWS; row++)
	{
	// --- UIRepeat: entering row (restoreTransientDescendantComponentStates) ---
	input.restoreTransientState(null, transientSnaps[row]);

	// --- (validation / rendering would happen here) ---
	boolean valid = input.isValid();
	Object sv = input.getSubmittedValue();

	// --- UIRepeat: leaving row (saveTransientDescendantComponentStates) ---
	transientSnaps[row] = input.saveTransientState(null);
	}
	});

	// ── 5a. APPLY_REQUEST_VALUES ───────────────────────────────────────────
	// Simulates UIRepeat.processDecodes(): for each row, restore EVH state,
	// let the renderer decode the request (setSubmittedValue), then save EVH state.
	// This is where Mojarra's plain-field submittedValue has a structural advantage:
	// its setSubmittedValue is a direct field write; ours goes through TransientStateHelper.
	header("Full row-switch — APPLY_REQUEST_VALUES (" + ROWS + " rows)");

	// Start with empty snapshots (fresh request, no prior per-row state).
	EditableValueHolderState[] applySnaps = new EditableValueHolderState[ROWS];
	resetInput(input);

	run("restore → decode (setSubmittedValue) → save", () ->
	{
	for (int row = 0; row < ROWS; row++)
	{
	// UIRepeat: entering row — restore previous EVH state (null on first visit)
	EditableValueHolderState prevEvh = applySnaps[row];
	if (prevEvh != null)
	{
	prevEvh.restoreState(input);
	}
	else
	{
	EditableValueHolderState.EMPTY.restoreState(input);
	}

	// Simulate renderer decode: sets the submitted form value on the component
	input.setSubmittedValue(SUBMITTED_VALUES[row]);

	// UIRepeat: leaving row — save updated EVH state
	applySnaps[row] = EditableValueHolderState.create(input);
	}
	});

	// ── 5b. PROCESS_VALIDATIONS — success ─────────────────────────────────
	// Simulates UIInput.validate() succeeding: reads submittedValue, converts it,
	// calls setValue(convertedValue) [which also sets localValueSet=true],
	// then clears submittedValue.
	header("Full row-switch — PROCESS_VALIDATIONS success (" + ROWS + " rows)");

	// Seed snapshots as if APPLY_REQUEST_VALUES already ran: each row has a submittedValue.
	EditableValueHolderState[] validateOkSnaps = new EditableValueHolderState[ROWS];
	for (int i = 0; i < ROWS; i++)
	{
	input.setSubmittedValue(SUBMITTED_VALUES[i]);
	validateOkSnaps[i] = EditableValueHolderState.create(input);
	}
	resetInput(input);

	run("restore → validate OK (setValue + clear sv) → save", () ->
	{
	for (int row = 0; row < ROWS; row++)
	{
	EditableValueHolderState evh = validateOkSnaps[row];
	if (evh != null)
	{
	evh.restoreState(input);
	}
	else
	{
	EditableValueHolderState.EMPTY.restoreState(input);
	}

	// Simulate UIInput.validate() success path:
	// converted = getConvertedValue(...) → skipped (no FacesContext needed)
	Object sv = input.getSubmittedValue(); // read submitted value
	input.setValue(sv); // store as local value (also sets localValueSet=true)
	input.setSubmittedValue(null); // clear submitted value after successful conversion

	validateOkSnaps[row] = EditableValueHolderState.create(input);
	}
	});

	// ── 5c. PROCESS_VALIDATIONS — failure ─────────────────────────────────
	// Simulates UIInput.validate() failing: reads submittedValue, marks invalid,
	// keeps submittedValue for re-display in the error state.
	header("Full row-switch — PROCESS_VALIDATIONS failure (" + ROWS + " rows)");

	// Seed snapshots with submitted values.
	EditableValueHolderState[] validateFailSnaps = new EditableValueHolderState[ROWS];
	for (int i = 0; i < ROWS; i++)
	{
	input.setSubmittedValue(SUBMITTED_VALUES[i]);
	validateFailSnaps[i] = EditableValueHolderState.create(input);
	}
	resetInput(input);

	run("restore → validate fail (setValid(false)) → save", () ->
	{
	for (int row = 0; row < ROWS; row++)
	{
	EditableValueHolderState evh = validateFailSnaps[row];
	if (evh != null)
	{
	evh.restoreState(input);
	}
	else
	{
	EditableValueHolderState.EMPTY.restoreState(input);
	}

	// Simulate UIInput.validate() failure path:
	// submittedValue is retained; component is marked invalid
	Object sv = input.getSubmittedValue(); // read (retained for error display)
	input.setValid(false); // mark invalid

	validateFailSnaps[row] = EditableValueHolderState.create(input);
	}
	});

	// ── 5d. UPDATE_MODEL_VALUES ────────────────────────────────────────────
	// Simulates UIInput.updateModel() succeeding: checks isValid + isLocalValueSet,
	// writes to EL model (skipped here), then resets the local value.
	// The reset path (setValue(null) + setLocalValueSet(false)) is the hot path
	// because setValue(null) internally also calls setLocalValueSet(true),
	// causing an add-then-remove cycle in TransientStateHelper.
	header("Full row-switch — UPDATE_MODEL_VALUES (" + ROWS + " rows)");

	// Seed snapshots as if PROCESS_VALIDATIONS success ran: each row has a local value.
	EditableValueHolderState[] updateSnaps = new EditableValueHolderState[ROWS];
	for (int i = 0; i < ROWS; i++)
	{
	input.setValue(SUBMITTED_VALUES[i]); // also sets localValueSet=true
	updateSnaps[i] = EditableValueHolderState.create(input);
	}
	resetInput(input);

	run("restore → updateModel (setValue(null) + setLocalValueSet(false)) → save", () ->
	{
	for (int row = 0; row < ROWS; row++)
	{
	EditableValueHolderState evh = updateSnaps[row];
	if (evh != null)
	{
	evh.restoreState(input);
	}
	else
	{
	EditableValueHolderState.EMPTY.restoreState(input);
	}

	// Simulate UIInput.updateModel() success path:
	if (input.isValid() && input.isLocalValueSet())
	{
	// expression.setValue(context.getELContext(), getLocalValue()) skipped
	input.setValue(null);
	input.setLocalValueSet(false);
	}

	updateSnaps[row] = EditableValueHolderState.create(input);
	}
	});

	System.out.println();
	}
	}