fix(ereader): restore cover position when navigating back to the cover

previous_page() set the on-cover flag but left current_position at the
first content block, so "showing the cover" had two different internal
representations depending on how you got there: block 0 on a fresh load,
block 1 after going forward and back.

current_position is what gets persisted, so closing the book while on the
cover reopened it past the cover, silently losing it.

Reset current_position to block 0 when returning to the cover, matching
where a fresh load sits.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

.dockerignore

@@ -0,0 +1,43 @@
+# Dockerfile.ci copies nothing from the context, but keeping it small makes
+# `docker build` fast and avoids shipping local state into the build.
+
+# Virtual environments
+venv/
+.venv/
+
+# Python cache and build output
+__pycache__/
+*.py[cod]
+*$py.class
+*.so
+build/
+dist/
+*.egg-info/
+*.egg
+
+# Git
+.git/
+
+# Test/coverage output
+.coverage
+coverage.json
+coverage.xml
+htmlcov/
+cov_info/
+.pytest_cache/
+.tox/
+.mypy_cache/
+
+# IDE
+.idea/
+.vscode/
+*.swp
+*.swo
+.claude/
+
+# Generated docs/images
+docs/images/
+
+# OS files
+.DS_Store
+Thumbs.db

.gitea/workflows/ci.yml

@@ -11,25 +11,47 @@ on:
 
 jobs:
   test:
-    runs-on: self-hosted
+    runs-on: linux/amd64
+    container:
+      # Built from Dockerfile.ci at the repo root. Carries Python 3.10-3.13,
+      # each in its own venv at /opt/py<version> with every dependency
+      # pre-installed, so a run downloads nothing.
+      image: gitea.tourolle.paris/dtourolle/pyweblayout-ci:latest
     strategy:
       matrix:
-        python-version: ['3.10', '3.12', '3.13']
+        python-version: ['3.10', '3.11', '3.12', '3.13']
+      fail-fast: false
+
+    env:
+      # pyWebLayout is a library: it is tested on every interpreter
+      # pyproject.toml's requires-python claims to support.
+      PYBIN: /opt/py${{ matrix.python-version }}/bin
+      # Badges and artifacts are published once, not once per matrix leg -
+      # four jobs racing to force-push the same branch is not a publish
+      # strategy. This leg is the one that publishes.
+      PUBLISH: ${{ matrix.python-version == '3.13' }}
+
     steps:
       - name: Checkout code
         uses: actions/checkout@v4
 
-      - name: Set up Python
-        uses: actions/setup-python@v4
-        with:
-          python-version: ${{ matrix.python-version }}
-          
-      - name: Verify declared dependencies are sufficient
+      - name: Install project
         run: |
-          # A clean venv with ONLY the declared runtime deps. If an import here
-          # fails, install_requires is incomplete and a real `pip install
-          # pyWebLayout` would fail the same way for a user.
-          python -m venv /tmp/clean-install
+          # --no-deps: dependencies are baked into the image. If a new one is
+          # added to pyproject.toml, add it to Dockerfile.ci and rebuild;
+          # the check below is what catches forgetting to.
+          $PYBIN/pip install -e . --no-deps
+          $PYBIN/python -c "import pyWebLayout; print('pyWebLayout', pyWebLayout.__file__)"
+
+      - name: Verify declared dependencies are sufficient
+        if: env.PUBLISH == 'true'
+        run: |
+          # A clean venv with ONLY the declared runtime deps, installed from
+          # the index rather than from the image. If an import here fails,
+          # pyproject.toml is incomplete and a real `pip install pyWebLayout`
+          # fails the same way for a user. This is the one step that is
+          # allowed to reach the network.
+          $PYBIN/python -m venv /tmp/clean-install
           /tmp/clean-install/bin/pip install --upgrade pip
           /tmp/clean-install/bin/pip install .
           /tmp/clean-install/bin/python -c "
@@ -40,152 +62,116 @@ jobs:
           print('clean install imports OK')
           "
 
-      - name: Install dependencies
-        run: |
-          python -m pip install --upgrade pip
-          # Install package in development mode, with the declared dev extra.
-          # Test dependencies belong in setup.cfg, not in an ad-hoc pip line.
-          pip install -e '.[dev]'
-
-      - name: Download initial failed badges
-        run: |
-          echo "Downloading initial failed badges..."
-          
-          # Create cov_info directory first
-          mkdir -p cov_info
-          
-          # Download failed badges as defaults
-          curl -o cov_info/coverage.svg "https://img.shields.io/badge/coverage-failed-red.svg"
-          curl -o cov_info/coverage-docs.svg "https://img.shields.io/badge/docs-failed-red.svg"
-          
-          echo "Initial failed badges created:"
-          ls -la cov_info/coverage*.svg
-          
       - name: Run tests with pytest
         id: pytest
         continue-on-error: true
         run: |
-          # Run tests with coverage
-          python -m pytest tests/ -v --cov=pyWebLayout --cov-report=term-missing --cov-report=json --cov-report=html --cov-report=xml
-          
+          $PYBIN/python -m pytest tests/ -v \
+            --cov=pyWebLayout \
+            --cov-report=term-missing \
+            --cov-report=json \
+            --cov-report=html \
+            --cov-report=xml
+
       - name: Check documentation coverage
         id: docs
         continue-on-error: true
         run: |
-          # Generate documentation coverage report
-          interrogate -v --ignore-init-method --ignore-init-module --ignore-magic --ignore-private --ignore-property-decorators --ignore-semiprivate --fail-under=80 pyWebLayout/
-          
+          $PYBIN/interrogate -v \
+            --ignore-init-method --ignore-init-module --ignore-magic \
+            --ignore-private --ignore-property-decorators --ignore-semiprivate \
+            --fail-under=80 pyWebLayout/
+
       - name: Lint with flake8
         run: |
           # Stop the build if there are Python syntax errors or undefined names
-          flake8 . --count --select=E9,F63,F7,F82 --show-source --statistics
+          $PYBIN/flake8 . --count --select=E9,F63,F7,F82 --show-source --statistics
           # Exit-zero treats all errors as warnings
-          flake8 . --count --exit-zero --max-complexity=10 --max-line-length=127 --statistics
-          
-      - name: Create coverage info directory
-        if: always()
+          $PYBIN/flake8 . --count --exit-zero --max-complexity=10 --max-line-length=127 --statistics
+
+      - name: Fail the job if tests failed
+        if: steps.pytest.outcome != 'success'
+        run: |
+          # pytest runs with continue-on-error so the badge steps below still
+          # execute; without this the job would report green on a red suite.
+          echo "::error::pytest failed on Python ${{ matrix.python-version }}"
+          exit 1
+
+      # ------------------------------------------------------------------
+      # Badges and artifacts - publishing leg only
+      # ------------------------------------------------------------------
+
+      - name: Prepare badge directory
+        if: always() && env.PUBLISH == 'true'
         run: |
           mkdir -p cov_info
-          echo "Created cov_info directory for coverage data"
-          
+          # Default to failed badges; the steps below overwrite them on success
+          curl -o cov_info/coverage.svg "https://img.shields.io/badge/coverage-failed-red.svg"
+          curl -o cov_info/coverage-docs.svg "https://img.shields.io/badge/docs-failed-red.svg"
+
       - name: Update test coverage badge on success
-        if: steps.pytest.outcome == 'success' && always()
+        if: always() && env.PUBLISH == 'true' && steps.pytest.outcome == 'success'
         run: |
-          echo "Tests passed! Generating successful coverage badge..."
-          
           if [ -f coverage.json ]; then
-            coverage-badge -o cov_info/coverage.svg -f
-            echo "✅ Test coverage badge updated with actual results"
+            $PYBIN/coverage-badge -o cov_info/coverage.svg -f
+            echo "✅ Test coverage badge updated"
           else
             echo "⚠️ No coverage.json found, keeping failed badge"
           fi
-          
-      - name: Update docs coverage badge on success  
-        if: steps.docs.outcome == 'success' && always()
+
+      - name: Update docs coverage badge on success
+        if: always() && env.PUBLISH == 'true' && steps.docs.outcome == 'success'
         run: |
-          echo "Docs check passed! Generating successful docs badge..."
-          
-          # Remove existing badge first to avoid overwrite error  
           rm -f cov_info/coverage-docs.svg
-          interrogate --generate-badge cov_info/coverage-docs.svg pyWebLayout/
-          echo "✅ Docs coverage badge updated with actual results"
-          
+          $PYBIN/interrogate --generate-badge cov_info/coverage-docs.svg pyWebLayout/
+          echo "✅ Docs coverage badge updated"
+
       - name: Generate coverage reports
-        if: steps.pytest.outcome == 'success'
+        if: env.PUBLISH == 'true' && steps.pytest.outcome == 'success'
         run: |
-          # Generate coverage summary for README
-          python -c "
-          import json
-          import os
-          # Read coverage data
+          $PYBIN/python -c "
+          import json, os
           if os.path.exists('coverage.json'):
-              with open('coverage.json', 'r') as f:
-                  coverage_data = json.load(f)
-              total_coverage = round(coverage_data['totals']['percent_covered'], 1)
-              # Create coverage summary file in cov_info directory
+              with open('coverage.json') as f:
+                  data = json.load(f)
+              total = round(data['totals']['percent_covered'], 1)
               with open('cov_info/coverage-summary.txt', 'w') as f:
-                  f.write(f'{total_coverage}%')
-              print(f'Test Coverage: {total_coverage}%')
-              covered_lines = coverage_data['totals']['covered_lines']
-              total_lines = coverage_data['totals']['num_statements']
-              print(f'Lines Covered: {covered_lines}/{total_lines}')
+                  f.write(f'{total}%')
+              print(f\"Test Coverage: {total}%\")
+              print(f\"Lines Covered: {data['totals']['covered_lines']}/{data['totals']['num_statements']}\")
           else:
               print('No coverage data found')
           "
-          
-          # Copy other coverage files to cov_info
           if [ -f coverage.json ]; then cp coverage.json cov_info/; fi
           if [ -f coverage.xml ]; then cp coverage.xml cov_info/; fi
           if [ -d htmlcov ]; then cp -r htmlcov cov_info/; fi
-          
+
       - name: Final badge status
-        if: always()
+        if: always() && env.PUBLISH == 'true'
         run: |
           echo "=== FINAL BADGE STATUS ==="
           echo "Test outcome: ${{ steps.pytest.outcome }}"
           echo "Docs outcome: ${{ steps.docs.outcome }}"
-          
-          if [ -f cov_info/coverage.svg ]; then
-            echo "✅ Test coverage badge: $(ls -lh cov_info/coverage.svg)"
-          else
-            echo "❌ Test coverage badge: MISSING"
-          fi
-          
-          if [ -f cov_info/coverage-docs.svg ]; then
-            echo "✅ Docs coverage badge: $(ls -lh cov_info/coverage-docs.svg)"
-          else
-            echo "❌ Docs coverage badge: MISSING"
-          fi
-          
-          echo "Coverage info directory contents:"
-          ls -la cov_info/ 2>/dev/null || echo "No cov_info directory found"
-          
+          ls -la cov_info/ 2>/dev/null || echo "No cov_info directory"
+
       - name: Upload coverage artifacts
+        if: always() && env.PUBLISH == 'true'
         uses: actions/upload-artifact@v3
         with:
           name: coverage-reports
-          path: |
-            cov_info/
-            
+          path: cov_info/
+
       - name: Commit badges to badges branch
-        if: github.ref == 'refs/heads/master'
+        if: env.PUBLISH == 'true' && github.ref == 'refs/heads/master'
         run: |
           git config --local user.email "action@gitea.local"
           git config --local user.name "Gitea Action"
-          
-          # Set the remote URL to use the token
+
           git remote set-url origin https://${{ secrets.PUSH_TOKEN }}@gitea.tourolle.paris/dtourolle/pyWebLayout.git
-          
-          # Create a new orphan branch for badges (this discards any existing badges branch)
+
+          # Orphan branch holding only the badges, force-pushed each time
           git checkout --orphan badges
-          
-          # Remove all files except cov_info
           find . -maxdepth 1 -not -name '.git' -not -name 'cov_info' -exec rm -rf {} + 2>/dev/null || true
-          
-          # Add only the coverage info directory
           git add -f cov_info/
-          
-          # Always commit (force overwrite)
-          echo "Force updating badges branch with new coverage data..."
           git commit -m "Update coverage badges [skip ci]"
           git push -f origin badges

Dockerfile.ci

@@ -0,0 +1,80 @@
+# CI test image for pyWebLayout
+# Build: docker build -f Dockerfile.ci -t gitea.tourolle.paris/dtourolle/pyweblayout-ci:latest .
+# Push:  docker push gitea.tourolle.paris/dtourolle/pyweblayout-ci:latest
+#
+# pyWebLayout is a library, so CI tests every interpreter pyproject.toml claims
+# to support rather than just one. All four are in this image and the workflow
+# matrix picks one per job; dependencies are pre-installed into each, so a CI
+# run downloads nothing.
+FROM ubuntu:24.04
+
+ENV DEBIAN_FRONTEND=noninteractive
+
+# deadsnakes carries the Python versions Ubuntu 24.04 does not ship
+RUN apt-get update && apt-get install -y --no-install-recommends \
+        ca-certificates \
+        gnupg \
+        software-properties-common \
+    && add-apt-repository -y ppa:deadsnakes/ppa \
+    && apt-get update && apt-get install -y --no-install-recommends \
+        # Interpreters. 3.12 is Ubuntu 24.04's own; the rest come from deadsnakes.
+        python3.10 python3.10-venv \
+        python3.11 python3.11-venv \
+        python3.12 python3.12-venv \
+        python3.13 python3.13-venv \
+        # Pillow needs these at runtime for font rasterisation and image IO
+        libfreetype6 \
+        libjpeg-turbo8 \
+        libopenjp2-7 \
+        libtiff6 \
+        zlib1g \
+        # Used by the workflow itself
+        curl \
+        git \
+        nodejs \
+    && rm -rf /var/lib/apt/lists/*
+
+# One venv per interpreter at a predictable path, /opt/py<version>. Ubuntu marks
+# its system Python externally-managed, so installing into venvs sidesteps that
+# without --break-system-packages, and keeps the four dependency sets isolated.
+#
+# The package list is written once so versions cannot drift between
+# interpreters. It mirrors pyproject.toml's runtime deps plus the test and dev
+# extras; keep the two in step.
+#
+# Deliberately NOT installed: pyWebLayout itself. The workflow installs the
+# checkout with --no-deps, so a job always tests the code under review.
+#
+# setuptools is pinned below 81 because that release dropped pkg_resources,
+# which coverage-badge still imports at startup. Without the pin the badge step
+# dies with ModuleNotFoundError. Revisit when coverage-badge stops using it.
+RUN for v in 3.10 3.11 3.12 3.13; do \
+        python$v -m venv /opt/py$v && \
+        /opt/py$v/bin/pip install --no-cache-dir --upgrade pip wheel && \
+        /opt/py$v/bin/pip install --no-cache-dir --upgrade "setuptools<81" && \
+        /opt/py$v/bin/pip install --no-cache-dir \
+            Pillow \
+            numpy \
+            pyphen \
+            beautifulsoup4 \
+            lxml \
+            pytest \
+            pytest-cov \
+            flask \
+            werkzeug \
+            ebooklib \
+            requests \
+            flake8 \
+            coverage-badge \
+            interrogate \
+        ; \
+    done
+
+# Fail the build rather than ship an image whose dependencies do not import
+RUN for v in 3.10 3.11 3.12 3.13; do \
+        echo "--- python$v ---" && \
+        /opt/py$v/bin/python -c \
+            "import sys, PIL, numpy, pyphen, bs4, pytest, flask, ebooklib, requests; \
+             print(sys.version.split()[0], 'deps OK')" \
+        ; \
+    done

README.md

@@ -231,6 +231,33 @@ current = manager.get_font_family()
 - **[pyWebLayout/layout/README_EREADER_API.md](pyWebLayout/layout/README_EREADER_API.md)** - EbookReader API reference
 - **API Reference** - See docstrings in source code
 
+## Continuous integration
+
+CI runs in a prebuilt container image rather than installing dependencies per
+job. The image carries Python 3.10, 3.11, 3.12 and 3.13, each in its own venv at
+`/opt/py<version>` with every dependency installed, so a run downloads nothing
+and the test matrix covers the whole range `pyproject.toml` claims to support.
+
+Rebuild and push the image whenever `Dockerfile.ci` changes — most often
+because a dependency was added to `pyproject.toml`:
+
+```bash
+docker build -f Dockerfile.ci -t gitea.tourolle.paris/dtourolle/pyweblayout-ci:latest .
+docker push gitea.tourolle.paris/dtourolle/pyweblayout-ci:latest
+```
+
+To reproduce a CI job locally:
+
+```bash
+docker run --rm -v "$PWD:/src:ro" gitea.tourolle.paris/dtourolle/pyweblayout-ci:latest bash -c '
+  mkdir -p /work && cp -a /src/. /work/ && cd /work && rm -rf venv .git
+  /opt/py3.13/bin/pip install -e . --no-deps -q
+  /opt/py3.13/bin/python -m pytest tests/ -q'
+```
+
+The workflow is [.gitea/workflows/ci.yml](.gitea/workflows/ci.yml). Badges and
+coverage artifacts are published from the 3.13 leg only.
+
 ## License
 
 MIT License

pyWebLayout/abstract/inline.py

@@ -3,12 +3,25 @@ from pyWebLayout.core import Hierarchical
 from pyWebLayout.style import Font
 from pyWebLayout.style.abstract_style import AbstractStyle
 from typing import Tuple, Union, List, Optional, Dict, Any, Callable
+from functools import lru_cache
 import pyphen
 
 # Import LinkType for type hints (imported at module level to avoid F821 linting error)
 from pyWebLayout.abstract.functional import LinkType
 
 
+@lru_cache(maxsize=16)
+def _hyphen_dict(language: Optional[str]) -> pyphen.Pyphen:
+    """
+    The pyphen dictionary for a language, reused across words.
+
+    Pyphen caches the parsed dictionary file itself, but rebuilding the wrapper
+    per word still costs about 40% of a hyphenation call, and hyphenation is
+    attempted for every word that overflows its line.
+    """
+    return pyphen.Pyphen(lang=language)
+
+
 class Word:
     """
     An abstract representation of a word in a document. Words can be split across
@@ -186,8 +199,7 @@ class Word:
             bool: True if the word was hyphenated, False otherwise.
         """
 
-        dic = pyphen.Pyphen(lang=self._style.language)
-        return list(dic.iterate(self._text))
+        return list(_hyphen_dict(self._style.language).iterate(self._text))
 
 
 ...

pyWebLayout/concrete/text.py

@@ -58,6 +58,15 @@ _width_cache: UsageCache = UsageCache(DEFAULT_WIDTH_CACHE_ENTRIES)
 _glyph_cache: SizedUsageCache = SizedUsageCache(DEFAULT_GLYPH_CACHE_BYTES, _glyph_entry_bytes)
 _glyph_subpixel_steps: int = DEFAULT_GLYPH_SUBPIXEL_STEPS
 
+# Every Line asks its font for the advance width of a space. That single
+# FreeTypeFont.getlength(" ") call costs ~18us -- two orders of magnitude more
+# than getmetrics() -- because PIL shapes the string from scratch each time, and
+# it lands once per line created, which dominates the cost of laying a line out.
+# There are only ever a handful of distinct fonts in play, so memoise per font
+# object. Values are wrapped in a 1-tuple because None is itself a legitimate
+# result (fonts that cannot report a length) and must not read as a cache miss.
+_space_advance_cache: Dict[Any, Tuple[Optional[int]]] = {}
+
 # Set to False the first time the fast rasterisation path is found to be
 # unavailable (e.g. a PIL build without the private ImageDraw internals it uses),
 # after which every Text falls back to ImageDraw.text().
@@ -98,6 +107,35 @@ def clear_text_caches():
     """Drop all cached widths and glyph bitmaps."""
     _width_cache.clear()
     _glyph_cache.clear()
+    _space_advance_cache.clear()
+
+
+def _space_advance(font) -> Optional[int]:
+    """
+    The font's own advance width for a space, in whole pixels.
+
+    None when the font cannot report one, which is the signal for callers to fall
+    back to their configured spacing range.
+    """
+    try:
+        cached = _space_advance_cache.get(font)
+    except TypeError:
+        # Unhashable font object; measure without caching.
+        cached = None
+    else:
+        if cached is not None:
+            return cached[0]
+
+    try:
+        value = int(round(font.getlength(" ")))
+    except (AttributeError, TypeError, ValueError):
+        value = None
+
+    try:
+        _space_advance_cache[font] = (value,)
+    except TypeError:
+        pass
+    return value
 
 
 def text_cache_stats() -> Dict[str, Any]:
@@ -215,7 +253,8 @@ class AlignmentHandler(ABC):
     def calculate_spacing_and_position(self, text_objects: List['Text'],
                                        available_width: int, min_spacing: int,
                                        max_spacing: int,
-                                       natural_spacing: Optional[int] = None
+                                       natural_spacing: Optional[int] = None,
+                                       total_width: Optional[float] = None
                                        ) -> Tuple[int, int, bool]:
         """
         Calculate the spacing between words and starting position for the line.
@@ -228,6 +267,11 @@ class AlignmentHandler(ABC):
             natural_spacing: The font's own space width. Ragged alignments use it
                 as a constant gap; justification ignores it. Defaults to
                 min_spacing when not supplied.
+            total_width: The summed width of `text_objects`, when the caller
+                already knows it. Purely an optimisation: a line asks its handler
+                to re-measure once per candidate word, and summing the whole line
+                each time makes filling a line quadratic in its word count. Omit
+                it and the sum is taken here as before.
 
         Returns:
             Tuple of (spacing_between_words, starting_x_position, overflow)
@@ -242,7 +286,8 @@ class LeftAlignmentHandler(AlignmentHandler):
                                        available_width: int,
                                        min_spacing: int,
                                        max_spacing: int,
-                                       natural_spacing: Optional[int] = None
+                                       natural_spacing: Optional[int] = None,
+                                       total_width: Optional[float] = None
                                        ) -> Tuple[int, int, bool]:
         """
         Calculate spacing and position for left-aligned text objects.
@@ -269,7 +314,8 @@ class LeftAlignmentHandler(AlignmentHandler):
         spacing = min_spacing if natural_spacing is None else natural_spacing
         spacing = max(min_spacing, min(max_spacing, int(spacing)))
 
-        text_length = sum([text.width for text in text_objects])
+        text_length = (sum([text.width for text in text_objects])
+                       if total_width is None else total_width)
         num_gaps = len(text_objects) - 1
 
         # The spacing is constant whether or not the content fits: tightening a
@@ -290,7 +336,8 @@ class CenterRightAlignmentHandler(AlignmentHandler):
     def calculate_spacing_and_position(self, text_objects: List['Text'],
                                        available_width: int, min_spacing: int,
                                        max_spacing: int,
-                                       natural_spacing: Optional[int] = None
+                                       natural_spacing: Optional[int] = None,
+                                       total_width: Optional[float] = None
                                        ) -> Tuple[int, int, bool]:
         """
         Centre/right alignment: constant word space, line shifted as a block.
@@ -300,7 +347,8 @@ class CenterRightAlignmentHandler(AlignmentHandler):
         the same spacing that will actually be used, so the line lands where it
         was measured to land.
         """
-        word_length = sum([word.width for word in text_objects])
+        word_length = (sum([word.width for word in text_objects])
+                       if total_width is None else total_width)
 
         # Handle single word case
         if len(text_objects) <= 1:
@@ -329,13 +377,42 @@ class JustifyAlignmentHandler(AlignmentHandler):
     """Handler for justified text with full justification."""
 
     def __init__(self):
-        # Store variable spacing for each gap to distribute remainder pixels
-        self._gap_spacings: List[int] = []
+        # The per-gap spacings are described by a plan rather than stored outright,
+        # and materialised on demand by the _gap_spacings property below. Fitting a
+        # line calls this handler once per candidate word and only ever looks at the
+        # first gap; building the whole list on each of those probes made adding n
+        # words to a line O(n^2). Only render() reads the full list.
+        self._gap_uniform: Optional[int] = None
+        self._gap_residual: int = 0
+        self._gap_count: int = 0
+        self._gap_cache: Optional[List[int]] = []
+
+    @property
+    def _gap_spacings(self) -> List[int]:
+        """The spacing to apply at each gap, left to right."""
+        if self._gap_cache is None:
+            if self._gap_uniform is not None:
+                self._gap_cache = [self._gap_uniform] * self._gap_count
+            else:
+                self._gap_cache = self._distribute(self._gap_residual, self._gap_count)
+        return self._gap_cache
+
+    @staticmethod
+    def _distribute(total: int, num_gaps: int) -> List[int]:
+        """Split `total` pixels across `num_gaps` gaps by cumulative rounding."""
+        gaps = []
+        placed = 0
+        for i in range(1, num_gaps + 1):
+            cumulative = int(round(total * i / num_gaps))
+            gaps.append(cumulative - placed)
+            placed = cumulative
+        return gaps
 
     def calculate_spacing_and_position(self, text_objects: List['Text'],
                                        available_width: int, min_spacing: int,
                                        max_spacing: int,
-                                       natural_spacing: Optional[int] = None
+                                       natural_spacing: Optional[int] = None,
+                                       total_width: Optional[float] = None
                                        ) -> Tuple[int, int, bool]:
         """
         Justified alignment distributes space to fill the entire line width.
@@ -347,14 +424,17 @@ class JustifyAlignmentHandler(AlignmentHandler):
         is min_spacing to ensure readability.
         """
 
-        word_length = sum([word.width for word in text_objects])
+        word_length = (sum([word.width for word in text_objects])
+                       if total_width is None else total_width)
         residual_space = available_width - word_length
         num_gaps = max(1, len(text_objects) - 1)
 
         # Check if we have enough space for minimum spacing
         if residual_space // num_gaps < min_spacing:
             # Not enough space - this is overflow
-            self._gap_spacings = [min_spacing] * num_gaps
+            self._gap_uniform = min_spacing
+            self._gap_count = num_gaps
+            self._gap_cache = None
             return min_spacing, 0, True
 
         # Distribute the residual by cumulative rounding rather than by taking a
@@ -365,14 +445,14 @@ class JustifyAlignmentHandler(AlignmentHandler):
         # ragged right edge on otherwise justified text. Rounding the running
         # total makes the gaps sum to the residual exactly.
         total = int(round(residual_space))
-        self._gap_spacings = []
-        placed = 0
-        for i in range(1, num_gaps + 1):
-            cumulative = int(round(total * i / num_gaps))
-            self._gap_spacings.append(cumulative - placed)
-            placed = cumulative
+        self._gap_uniform = None
+        self._gap_residual = total
+        self._gap_count = num_gaps
+        self._gap_cache = None
 
-        return self._gap_spacings[0], 0, False
+        # The first gap is the whole of the plan that fitting needs, and it falls
+        # out of the same cumulative rounding as _distribute would give it.
+        return int(round(total / num_gaps)), 0, False
 
 
 class Text(Renderable, Queriable):
@@ -689,6 +769,9 @@ class Line(Box):
         """
         super().__init__(origin, size, callback, sheet, mode, halign, valign)
         self._text_objects: List['Text'] = []  # Store Text objects directly
+        # Prefix sums of the widths in _text_objects, kept in step by _push_text /
+        # _pop_text. Element 0 is the empty sum. See _push_text for the rationale.
+        self._width_prefix: List[float] = [0.0]
         self._spacing = spacing  # (min_spacing, max_spacing)
         self._font = font if font else Font()  # Use default font if none provided
         self._current_width = 0  # Track the current width used
@@ -704,10 +787,7 @@ class Line(Box):
 
         # The font's own space advance. Ragged alignments use this as their
         # constant word gap rather than stretching to fill the measure.
-        try:
-            self._natural_spacing = int(round(self._font.font.getlength(" ")))
-        except (AttributeError, TypeError, ValueError):
-            self._natural_spacing = None
+        self._natural_spacing = _space_advance(self._font.font)
 
         # Hyphenation configuration parameters
         self._min_word_length_for_brute_force = min_word_length_for_brute_force
@@ -771,6 +851,45 @@ class Line(Box):
         """Set the next line in sequence"""
         self._next = line
 
+    @property
+    def _content_width(self) -> float:
+        """Summed width of the line's current contents."""
+        return self._width_prefix[-1]
+
+    def _push_text(self, text: 'Text'):
+        """
+        Append a Text to the line, keeping the running width sum in step.
+
+        Fitting a word is a trial: the candidate is pushed, measured, and popped
+        again if it did not fit, so the line's contents churn far more often than
+        they grow. Tracking the sum here rather than re-adding every width on each
+        measurement is what keeps filling a line linear in its word count.
+
+        The sum is kept as a prefix list rather than as one accumulator that is
+        added to and subtracted from. Widths are floats, so `(total + w) - w` need
+        not give back `total` exactly, and a drift of one ulp is enough to flip an
+        overflow decision on a line that ends flush. Truncating a prefix list
+        restores the earlier total bit for bit, and each entry is built by the same
+        left-to-right addition sum() would perform.
+        """
+        self._text_objects.append(text)
+        self._width_prefix.append(self._width_prefix[-1] + text.width)
+
+    def _pop_text(self) -> 'Text':
+        """Remove the last Text from the line, keeping the width sum in step."""
+        text = self._text_objects.pop()
+        self._width_prefix.pop()
+        return text
+
+    def _measure(self, handler: Optional[AlignmentHandler] = None
+                 ) -> Tuple[int, int, bool]:
+        """Ask an alignment handler to place the line's current contents."""
+        if handler is None:
+            handler = self._alignment_handler
+        return handler.calculate_spacing_and_position(
+            self._text_objects, self._size[0], self._spacing[0], self._spacing[1],
+            self._natural_spacing, self._content_width)
+
     def add_word(self,
                  word: 'Word',
                  part: Optional[Text] = None) -> Tuple[bool,
@@ -789,7 +908,7 @@ class Line(Box):
         """
         # First, add any pretext from previous hyphenation
         if part is not None:
-            self._text_objects.append(part)
+            self._push_text(part)
             self._words.append(word)
             part.add_line(self)
 
@@ -818,10 +937,8 @@ class Line(Box):
                 line=self)
         else:
             text = Text.from_word(word, self._draw)
-        self._text_objects.append(text)
-        spacing, position, overflow = self._alignment_handler.calculate_spacing_and_position(
-            self._text_objects, self._size[0], self._spacing[0], self._spacing[1],
-                self._natural_spacing)
+        self._push_text(text)
+        spacing, position, overflow = self._measure()
 
         if not overflow:
             # Word fits! Add it completely
@@ -833,7 +950,7 @@ class Line(Box):
             return True, None
 
         # Word doesn't fit, remove it and try hyphenation
-        _ = self._text_objects.pop()
+        self._pop_text()
 
         # Step 1: Try pyphen hyphenation
         pyphen_splits = word.possible_hyphenation()
@@ -866,11 +983,9 @@ class Line(Box):
                     source=word)
 
                 # Check if first part fits
-                self._text_objects.append(first_text)
-                spacing, position, overflow = self._alignment_handler.calculate_spacing_and_position(
-                    self._text_objects, self._size[0], self._spacing[0], self._spacing[1],
-                self._natural_spacing)
-                _ = self._text_objects.pop()
+                self._push_text(first_text)
+                spacing, position, overflow = self._measure()
+                self._pop_text()
 
                 if not overflow:
                     # This split fits! Add it to valid options
@@ -883,7 +998,7 @@ class Line(Box):
             first_text, second_text, spacing, position = best_split
 
             # Apply the split
-            self._text_objects.append(first_text)
+            self._push_text(first_text)
             first_text.line = self
             word.add_concete((first_text, second_text))
             self._spacing_render = spacing
@@ -894,7 +1009,7 @@ class Line(Box):
         # Step 3: Try brute force hyphenation (only for long words)
         if len(word.text) >= self._min_word_length_for_brute_force:
             # Calculate available space for the word
-            word_length = sum([text.width for text in self._text_objects])
+            word_length = self._content_width
             spacing_length = self._spacing[0] * max(0, len(self._text_objects) - 1)
             remaining = self._size[0] - word_length - spacing_length
 
@@ -938,10 +1053,8 @@ class Line(Box):
                             source=word)
 
                         # Verify the first part actually fits
-                        self._text_objects.append(first_text)
-                        spacing, position, overflow = self._alignment_handler.calculate_spacing_and_position(
-                            self._text_objects, self._size[0], self._spacing[0], self._spacing[1],
-                self._natural_spacing)
+                        self._push_text(first_text)
+                        spacing, position, overflow = self._measure()
 
                         if not overflow:
                             # Brute force split works!
@@ -954,7 +1067,7 @@ class Line(Box):
                             return True, second_text
                         else:
                             # Doesn't fit, remove it
-                            _ = self._text_objects.pop()
+                            self._pop_text()
 
         # Step 4: Word cannot be hyphenated or split, move to next line
         return False, None
@@ -972,9 +1085,7 @@ class Line(Box):
         # justified paragraph.
         handler = self.render_alignment_handler
         if len(self._text_objects) > 0:
-            spacing, position, overflow = handler.calculate_spacing_and_position(
-                self._text_objects, self._size[0], self._spacing[0], self._spacing[1],
-                self._natural_spacing)
+            spacing, position, overflow = self._measure(handler)
             self._spacing_render = spacing
             self._position_render = position
 
@@ -982,28 +1093,33 @@ class Line(Box):
 
         # Start x_cursor at line origin plus any alignment offset
         x_cursor = self._origin[0] + self._position_render
-        for i, text in enumerate(self._text_objects):
+
+        # Everything the loop needs that does not vary per word is resolved once.
+        # Only justified lines carry per-gap spacings; every other alignment uses
+        # the single spacing figured above.
+        texts = self._text_objects
+        last = len(texts) - 1
+        draw = self._draw
+        default_spacing = self._spacing_render
+        gaps = handler._gap_spacings if isinstance(handler, JustifyAlignmentHandler) else ()
+        gap_count = len(gaps)
+
+        for i, text in enumerate(texts):
             # Update text draw context to current draw context
-            text._draw = self._draw
+            text._draw = draw
             text.set_origin(np.array([x_cursor, y_cursor]))
 
             # Determine next text object for continuous decoration
-            next_text = self._text_objects[i + 1] if i + \
-                1 < len(self._text_objects) else None
+            next_text = texts[i + 1] if i < last else None
 
             # Get the spacing for this specific gap (variable for justified text)
-            if isinstance(handler, JustifyAlignmentHandler) and \
-               hasattr(handler, '_gap_spacings') and \
-               i < len(handler._gap_spacings):
-                current_spacing = handler._gap_spacings[i]
-            else:
-                current_spacing = self._spacing_render
+            current_spacing = gaps[i] if i < gap_count else default_spacing
 
             # Render with next text information for continuous underline/strikethrough
             text.render(next_text, current_spacing)
             # Add text width, then spacing only if there are more words
             x_cursor += text.width
-            if i < len(self._text_objects) - 1:
+            if i < last:
                 x_cursor += current_spacing
 
     def query_point(self, point: Tuple[int, int]) -> Optional['QueryResult']:

pyWebLayout/io/readers/html_extraction.py

@@ -403,13 +403,13 @@ def extract_words_from_nodes(nodes: List, context: StyleContext) -> List[Word]:
             continue
 
         if isinstance(child, NavigableString):
-            # Plain text - split into words
-            text = str(child).strip()
-            if text:
-                word_texts = text.split()
-                for word_text in word_texts:
-                    if word_text:
-                        words.append(Word(word_text, context.font, context.background))
+            # Plain text - split into words. Argument-less str.split() already
+            # discards surrounding whitespace and never yields an empty string, so
+            # it needs neither a preceding strip() nor a per-word emptiness test.
+            font = context.font
+            background = context.background
+            words.extend([Word(word_text, font, background)
+                          for word_text in str(child).split()])
         elif isinstance(child, Tag):
             # Special handling for <a> tags (hyperlinks)
             if child.name.lower() == "a":

pyWebLayout/layout/document_layouter.py

@@ -163,12 +163,9 @@ def paragraph_layouter(paragraph: Paragraph,
             y_cursor = page._current_y_offset
         x_cursor = page.content_origin[0]
 
-        # Create a temporary Text object to calculate word width
-        if word:
-            temp_text = Text.from_word(word, page.measurement_draw)
-            temp_text.width
-        else:
-            pass
+        # `word` is accepted for call-site readability only: the line that is about
+        # to be created measures it when it is added, so measuring it here as well
+        # only paid for a Text object that was immediately discarded.
 
         return Line(
             spacing=word_spacing_constraints,

pyWebLayout/layout/ereader_layout.py

@@ -43,6 +43,19 @@ class RenderingPosition:
     remaining_pretext: Optional[str] = None     # Hyphenated word continuation
     page_y_offset: int = 0                     # Vertical position on page
 
+    def _key(self) -> Tuple[Any, ...]:
+        """
+        The fields in declaration order.
+
+        Copying, comparing and hashing a position all used to go through
+        dataclasses.asdict, which walks the field list and deep-copies each value.
+        Every field here is an immutable scalar, so that traversal bought nothing
+        and these three run constantly during page navigation and buffer lookups.
+        """
+        return (self.chapter_index, self.block_index, self.word_index,
+                self.table_row, self.table_col, self.list_item_index,
+                self.remaining_pretext, self.page_y_offset)
+
     def to_dict(self) -> Dict[str, Any]:
         """Serialize position for saving to file/database"""
         return asdict(self)
@@ -54,17 +67,17 @@ class RenderingPosition:
 
     def copy(self) -> 'RenderingPosition':
         """Create a copy of this position"""
-        return RenderingPosition(**asdict(self))
+        return RenderingPosition(*self._key())
 
     def __eq__(self, other) -> bool:
         """Check if two positions are equal"""
         if not isinstance(other, RenderingPosition):
             return False
-        return asdict(self) == asdict(other)
+        return self._key() == other._key()
 
     def __hash__(self) -> int:
         """Make position hashable for use as dict key"""
-        return hash(tuple(asdict(self).values()))
+        return hash(self._key())
 
 
 class ChapterInfo:

pyWebLayout/layout/ereader_manager.py

@@ -453,6 +453,12 @@ class EreaderLayoutManager:
         # Special case: if at the beginning of content and there's a cover, go back to it
         if self._has_cover and self._is_at_beginning() and not self._on_cover_page:
             self._on_cover_page = True
+            # Restore the canonical cover position. Being on the cover must have a
+            # single representation: a fresh load sits at block 0 with the cover
+            # showing, so returning to the cover has to land there too. Leaving the
+            # position at the first content block saves a position that reopens past
+            # the cover, silently losing it.
+            self.current_position = RenderingPosition()
             self._notify_position_changed()
             return self.get_current_page()
 

pyWebLayout/style/abstract_style.py

@@ -112,7 +112,17 @@ class AbstractStyle:
         Since this is a frozen dataclass, it should be hashable by default,
         but we provide a custom implementation to ensure all fields are
         properly considered and to handle the Union types correctly.
+
+        The result is memoised on first use. Styles are used as dictionary keys
+        throughout parsing and style resolution, and five of the fields are enum
+        members whose own __hash__ is a Python-level call, so rebuilding the
+        15-tuple on every lookup was a measurable share of document parsing. The
+        class is frozen, so the value cannot go stale.
         """
+        cached = self.__dict__.get('_hash_cache')
+        if cached is not None:
+            return cached
+
         # Convert all values to hashable forms
         hashable_values = (
             self.font_family,
@@ -132,7 +142,9 @@ class AbstractStyle:
             self.parent_style_id
         )
 
-        return hash(hashable_values)
+        result = hash(hashable_values)
+        object.__setattr__(self, '_hash_cache', result)
+        return result
 
     def merge_with(self, other: 'AbstractStyle') -> 'AbstractStyle':
         """

tests/abstract/test_abstract_blocks.py

@@ -372,8 +372,12 @@ class TestImagePIL(unittest.TestCase):
         cls.flask_thread = threading.Thread(target=cls.flask_server.serve_forever, daemon=True)
         cls.flask_thread.start()
 
-        # Wait for server to be ready with health check
-        max_wait = 5  # Maximum 5 seconds
+        # Wait for server to be ready with health check.
+        # Generous, because this now raises rather than falling through
+        # silently: on a loaded CI runner the accept loop can take several
+        # seconds to get scheduled, and a spurious failure here is worse than
+        # a slow one. The loop exits as soon as the server answers.
+        max_wait = 30
         wait_interval = 0.1  # Check every 100ms
         elapsed = 0