All libraries should implement this."""
raise NotImplementedError()
+ def search(self, string):
+ """Returns an iterable object of mangas in this library that
+ matches the search string in a library-dependent manner. While
+ each library is at liberty to define its own matching
+ criteria, it is probably likely to involve something akin to
+ searching for keywords in the titles of the library.
+
+ Searching may return very many results and may be slow to
+ iterate.
+
+ Not all libraries need implement this."""
+ raise NotImplementedError()
+
+ def byid(self, id):
+ """Returns a previously known manga by its string ID, or
+ raises KeyError if no such manga could be found.
+
+ All libraries should implement this."""
+ raise KeyError(id)
+
def __iter__(self):
"""Return an iterator of all known mangas in this library.
class pagetree(object):
"""Base class for objects in the tree of pages and pagelists.
- All pagetree objects should contain an attribute `stack', contains
- a list of pairs. The last pair in the list should be the pagetree
- object which yielded this pagetree object, along with the index
- which yielded it. Every non-last pair should be the same
+ All pagetree objects should contain an attribute `stack',
+ containing a list of pairs. The last pair in the list should be
+ the pagetree object which yielded this pagetree object, along with
+ the index which yielded it. Every non-last pair should be the same
information for the pair following it. The only objects with empty
- `stack' lists should be `manga' objects."""
- pass
+ `stack' lists should be `manga' objects.
+
+ All non-root pagetree objects should also contain an attribute
+ `id', which should be a string that can be passed to the `byid'
+ function of its parent node to recover the node. Such string ID
+ should be more persistent than the node's numeric index in the
+ parent.
+
+ All pagetree objects should contain an attribute `name',
+ containing some human-readable Unicode representation of the
+ pagelist."""
+
+ def idlist(self):
+ """Returns a list of the IDs necessary to resolve this node
+ from the root node."""
+ if len(self.stack) == 0:
+ return []
+ return self.stack[-1][0].idlist() + [self.id]
+
+ def byidlist(self, idlist):
+ if len(idlist) == 0:
+ return self
+ return self.byid(idlist[0]).byidlist(idlist[1:])
class pagelist(pagetree):
"""Class representing a list of either pages, or nested
- pagelists. Might be, for instance, a volume or a chapter.
-
- All pagelists should contain an attribute `name', containing some
- human-readable Unicode representation of the pagelist."""
+ pagelists. Might be, for instance, a volume or a chapter."""
def __len__(self):
"""Return the number of (direct) sub-nodes in this pagelist.
All pagelists need to implement this."""
raise NotImplementedError()
+ def byid(self, id):
+ """Return the direct sub-node of this pagelist which has the
+ given string ID. If none is found, a KeyError is raised.
+
+ This default method iterates the children of this node, but
+ may be overridden by some more efficient implementation.
+ """
+ for ch in self:
+ if ch.id == id:
+ return ch
+ raise KeyError(id)
+
class manga(pagelist):
"""Class reprenting a single manga. Includes the pagelist class,
- and all constraints valid for it."""
+ and all constraints valid for it.
+
+ A manga is a root pagetree node, but should also contain an `id'
+ attribute, which can be used to recover the manga from its
+ library's `byid' function."""
pass
class page(pagetree):
when exiting the with-scope.
All imgstreams should contain an attribute `ctype', being the
- Content-Type of the image being read by the stream."""
+ Content-Type of the image being read by the stream, and `clen`,
+ being either an int describing the total number of bytes in the
+ stream, or None if the value is not known in advance."""
def __enter__(self):
return self
def __exit__(self, *exc_info):
self.close()
+ def fileno(self):
+ """If reading the imgstream may block, fileno() should return
+ a file descriptor that can be polled. If fileno() returns
+ None, that should mean that reading will not block."""
+ return None
+
def close(self):
"""Close this stream."""
raise NotImplementedError()
- def read(self, sz = None):
+ def read(self, sz=None):
"""Read SZ bytes from the stream, or the entire rest of the
stream of SZ is not given."""
raise NotImplementedError()
+class stdimgstream(imgstream):
+ """A standard implementation of imgstream, for libraries which
+ have no particular implementation requirements."""
+
+ def __init__(self, url):
+ import urllib.request
+ self.bk = urllib.request.urlopen(url)
+ ok = False
+ try:
+ if self.bk.getcode() != 200:
+ raise IOError("Server error: " + str(self.bk.getcode()))
+ self.ctype = self.bk.info()["Content-Type"]
+ self.clen = int(self.bk.info()["Content-Length"])
+ ok = True
+ finally:
+ if not ok:
+ self.bk.close()
+
+ def fileno(self):
+ return self.bk.fileno()
+
+ def close(self):
+ self.bk.close()
+
+ def read(self, sz=None):
+ if sz is None:
+ return self.bk.read()
+ else:
+ return self.bk.read(sz)
+
class cursor(object):
def __init__(self, ob):
- self.cur = self.descend(ob)
+ if isinstance(ob, cursor):
+ self.cur = ob.cur
+ else:
+ self.cur = self.descend(ob)
- def descend(self, ob):
+ def descend(self, ob, last=False):
while isinstance(ob, pagelist):
- ob = ob[0]
+ ob = ob[len(ob) - 1 if last else 0]
if not isinstance(ob, page):
raise TypeError("object in page tree was unexpectedly not a pagetree")
return ob
raise StopIteration()
def prev(self):
- for n, i in reversed(self.cur,stack):
+ for n, i in reversed(self.cur.stack):
if i > 0:
- self.cur = self.descend(n[i - 1])
+ self.cur = self.descend(n[i - 1], True)
return self.cur
raise StopIteration()
def __iter__(self):
return self
+
+loaded = {}
+def findlib(name):
+ def load(name):
+ import importlib
+ mod = importlib.import_module(name)
+ if not hasattr(mod, "library"):
+ raise ImportError("module " + name + " is not a manga library")
+ return mod.library()
+ if name not in loaded:
+ try:
+ loaded[name] = load("manga." + name)
+ except ImportError:
+ loaded[name] = load(name)
+ return loaded[name]