Add build-asy.py script to build Asymptote figures.

diff --git a/src/figures/asy/build-asy.py b/src/figures/asy/build-asy.py
new file mode 100755 (executable)
index 0000000..675860d
--- /dev/null
+++ b/src/figures/asy/build-asy.py
@@ -0,0 +1,122 @@
+#!/usr/bin/env python3
+
+import hashlib as _hashlib
+import os as _os
+import os.path as _os_path
+import subprocess as _subprocess
+import sys as _sys
+
+
+ASY = ['asy', '-noprc', '-render', '0']
+
+
+def load_cache(path):
+    cache = {}
+    try:
+        with open(path, 'r') as f:
+            for line in f:
+                line = line.strip()
+                if line.startswith('#') or not line:
+                    continue
+                original,hash = line.split('\t')
+                cache[original] = hash
+    except IOError as e:
+        print(e)
+    return cache
+
+def save_cache(path, cache):
+    with open(path, 'w') as f:
+        for original,hash in sorted(cache.items()):
+            f.write('{}\t{}\n'.format(original, hash))
+
+def file_hash(path):
+    with open(path, 'rb') as f:
+        h = _hashlib.sha256(f.read())
+    return str(h.hexdigest())
+
+def find_originals(root):
+    originals = {}
+    for dirpath,dirnames,filenames in _os.walk(root):
+        if dirpath == _os_path.abspath(asydir):
+            continue
+        for filename in filenames:
+            if filename.endswith('.asy'):
+                path = _os_path.join(dirpath, filename)
+                if _os_path.islink(path):
+                    continue
+                with open(path, 'rb') as f:
+                    text = f.read()
+                originals[path] = text
+    return originals
+
+def match_original(path, originals):
+    with open(path, 'rb') as f:
+        text = f.read()
+    for o_path,o_text in originals.items():
+        if o_text in text:
+            return o_path
+    raise KeyError(path)
+
+def is_outdated(source, target, cache):
+    if not _os_path.exists(target):
+        return True
+    hash = file_hash(source)
+    if hash == cache.get(source, None):
+        return False
+    return True
+    #source_time = _os.stat(source).st_mtime
+    #target_time = _os.stat(target).st_mtime
+    #return source_time > target_time
+
+def symlink(source, link_name):
+    if (_os_path.exists(link_name) and
+        _os_path.realpath(link_name) != _os_path.realpath(source)):
+        _os.remove(link_name)  # old link points somewhere else
+    if not _os_path.exists(link_name):
+        print('link {} -> {}'.format(link_name, source))
+        _os.symlink(source, link_name)
+
+def build_asy(path, originals, cache):
+    original_path = match_original(path, originals)
+    print('matched {} with {}'.format(path, original_path))
+    original_dir = _os_path.dirname(original_path)
+    install_dir,filename = _os_path.split(path)
+    link_path = _os_path.join(original_dir, filename)
+    symlink(path, link_path)
+    root,ext = _os_path.splitext(filename)
+    output_filename = root + '.tex'
+    output_path = _os_path.join(original_dir, output_filename)
+    if is_outdated(original_path, output_path, cache):
+        print('rebuild {}'.format(path))
+        args = ASY + [filename]
+        p = _subprocess.Popen(args, cwd=original_dir)
+        stdout,stderr = p.communicate()
+        status = p.wait()
+        assert status == 0, (status, stderr)
+        cache[original_path] = file_hash(original_path)
+    for output_filename in _os.listdir(original_dir):
+        output_path = _os_path.join(original_dir, output_filename)
+        if (output_filename.startswith(root) and
+            not _os_path.islink(output_path)):
+            install_path = _os_path.join(install_dir, output_filename)
+            symlink(output_path, install_path)
+
+
+if __name__ == '__main__':
+    asydir = '.'
+    if len(_sys.argv) >= 2:
+        asydir = _sys.argv[1]
+
+    cache_path = _os_path.join(asydir, '.cache')
+    cache = load_cache(cache_path)
+    originals = find_originals(
+        root=_os_path.abspath(_os_path.join(asydir, '..')))
+    filenames = _os.listdir(asydir)
+    try:
+        for filename in _os.listdir(asydir):
+            source_path = _os_path.abspath(_os_path.join(asydir, filename))
+            if _os_path.islink(source_path) or filename == '.cache':
+                continue
+            build_asy(source_path, originals, cache)
+    finally:
+        save_cache(cache_path, cache)