Specify a custom user-agent string for all default requests.

[automanga.git] / manga / lib.py

diff --git a/manga/lib.py b/manga/lib.py
index 0890eaf..662ecc3 100644 (file)
--- a/manga/lib.py
+++ b/manga/lib.py
@@ -9,6 +9,26 @@ class library(object):
         All libraries should implement this."""
         raise NotImplementedError()
 
         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.
 
     def __iter__(self):
         """Return an iterator of all known mangas in this library.
 


@@ -18,20 +38,38 @@ class library(object):
 class pagetree(object):
     """Base class for objects in the tree of pages and pagelists.
 
 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
     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
 
 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.
 
     def __len__(self):
         """Return the number of (direct) sub-nodes in this pagelist.


@@ -49,9 +87,25 @@ class pagelist(pagetree):
         All pagelists need to implement this."""
         raise NotImplementedError()
 
         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,
 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):
     pass
 
 class page(pagetree):


@@ -75,7 +129,9 @@ class imgstream(object):
     when exiting the with-scope.
 
     All imgstreams should contain an attribute `ctype', being the
     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 __enter__(self):
         return self


@@ -83,39 +139,95 @@ class imgstream(object):
     def __exit__(self, *exc_info):
         self.close()
 
     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 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()
 
         """Read SZ bytes from the stream, or the entire rest of the
         stream of SZ is not given."""
         raise NotImplementedError()
 

-class pageiter(object):
-    def __init__(self, root):
-        self.nstack = [0]
-        self.lstack = [root]
+class stdimgstream(imgstream):
+    """A standard implementation of imgstream, for libraries which
+    have no particular implementation requirements."""
+
+    def __init__(self, url):
+        import urllib.request
+        req = urllib.request.Request(url, headers={"User-Agent": "automanga/1"})
+        print(req)
+        self.bk = urllib.request.urlopen(req)
+        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):
+        if isinstance(ob, cursor):
+            self.cur = ob.cur
+        else:
+            self.cur = self.descend(ob)
+
+    def descend(self, ob, last=False):
+        while isinstance(ob, pagelist):
+            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

 
     def next(self):
 
     def next(self):

-        while True:
-            if len(self.nstack) == 0:
-                raise StopIteration
-            try:
-                node = self.lstack[-1][self.nstack[-1]]
-            except IndexError:
-                self.lstack.pop()
-                self.nstack.pop()
-                if len(self.nstack) > 0:
-                    self.nstack[-1] += 1
-                continue
-            if isinstance(node, page):
-                nl = tuple(self.nstack)
-                self.nstack[-1] += 1
-                return nl, node
-            elif isinstance(node, pagelist):
-                self.lstack.append(node)
-                self.nstack.append(0)
+        for n, i in reversed(self.cur.stack):
+            if i < len(n) - 1:
+                self.cur = self.descend(n[i + 1])
+                return self.cur
+        raise StopIteration()
+
+    def prev(self):
+        for n, i in reversed(self.cur.stack):
+            if i > 0:
+                self.cur = self.descend(n[i - 1], True)
+                return self.cur
+        raise StopIteration()

 
     def __iter__(self):
         return self
 
     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]