| Age | Commit message (Collapse) | Author |
|---|
|
|
|
Silly mistake in previous commit.
|
|
All in one command line replacement for muxpsdraw and mupdfdraw.
|
|
We only open one instance of freetype per document. We therefore
have to ensure that only 1 call to it takes place at a time. We
introduce a lock for this purpose (FZ_LOCK_FREETYPE), and arrange
to take/release it as required.
We also update the font context so it is properly shared.
|
|
This simplifies other locking issues (notably freetype).
|
|
|
|
This is a significant change to the use of locks in MuPDF.
Previously, the user had the option of passing us lock/unlock
functions for a single mutex as part of the allocation struct.
Now we remove these entries from the allocation struct, and
make a separate 'locks' struct. This enables people to use
fz_alloc_default with locking.
If multithreaded operation is required, then the user is
required to create FZ_LOCK_MAX mutexes, which will be locked
or unlocked by MuPDF calling the lock/unlock functions within
the new fz_locks_context structure passed in at context creation.
These mutexes are not required to be recursive (they may be, but
MuPDF should never call them in this way). MuPDF avoids deadlocks
by imposing a locking ordering on itself; a thread will never take
lock n, if it already holds any lock i for which 0 <= i <= n.
Currently, there are 4 locks used within MuPDF.
Lock 0: The alloc lock; taken around all calls to user supplied
(or default) allocation functions. Also taken around all accesses
to the refs field of storable items.
Lock 1: The store lock; taken whenever the store data structures
(specifically the linked list pointers) are accessed.
Lock 2: The file lock; taken whenever a thread is accessing the raw
file. We use the debugging macros to insist that this is held
whenever we do a file based seek or read. We also insist that this
is never held when we resolve an indirect reference, as this can
have the effect of moving the file pointer.
Lock 3: The glyphcache lock; taken whenever a thread calls freetype,
or accesses the glyphcache data structures. This introduces some
complexities w.r.t type3 fonts.
Locking can be hugely problematic, so to ease our minds as to
the correctness of this code, we introduce some debugging macros.
These compile away to nothing unless FITZ_DEBUG_LOCKING is defined.
fz_assert_lock_held(ctx, lock) checks that we hold lock.
fz_assert_lock_not_held(ctx, lock) checks that we do not hold lock.
In addition fz_lock_debug_lock and fz_lock_debug_unlock are used
on every fz_lock/fz_unlock to check the validity of the operation
we are performing - in particular it checks that we do/do not already
hold the lock we are trying to take/drop, and that by taking this
lock we are not violating our defined locking order.
The RESOLVE macro (used throughout the code to check whether we need
to resolve an indirect reference) calls fz_assert_lock_not_held to
ensure that we aren't about to resolve an indirect reference (and
hence move the stream pointer) when the file is locked.
In order to implement the file locking properly, pdf_open_stream
(and friends) now lock the file as a side effect (because they
fz_seek to the start of the stream). The lock is automatically
dropped on an fz_close of such streams.
Previously, the glyph cache was created in a context when it was first
required; this presents problems as it can be shared between several
contexts or not, depending on whether it is created before the
contexts are cloned. We now always create it at startup, so it is
always shared.
This means that we need reference counting for the glyph caches.
Added here.
In fz_render_glyph, we take the glyph cache lock, and check to see
whether the glyph is in the cache. If it is, we bump the refcount,
drop the lock and returned the cached character. If it is not, we
need to render the character.
For freetype based fonts we keep the lock throughout the rendering
process, thus ensuring that freetype is only called in a single
threaded manner.
For type3 fonts, however, we need to invoke the interpreter again
to render the glyph streams. This can require reentrance to this
routine. We therefore drop the glyph cache lock, call the
interpreter to render us our pixmap, and take the lock again.
This dropping and retaking of the lock introduces a possible race
condition; 2 threads may try to render the same character at the
same time. We therefore modify our hash table insert routines to
behave differently if it comes to insert an entry only to find
that an entry with the same key is already there.
We spot this case; if we have just rendered a type3 glyph and when
we try to insert it into the cache discover that someone has beaten
us to it, we just discard our entry and use the cached one.
Hopefully this will seldom be a problem in practise; to solve it
properly would require greater complexity (probably involving
spotting that another thread is already working on the desired
rendering, and sleeping on a semaphore until it completes).
|
|
When cloning a context, it's generally best to return your new
context, rather than the one you cloned from.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Thanks to Zeniko for this; one line fix in the fax decoder, to
cope with a case at the start of lines.
This fixes:
x - 1d faxd overflow.pdf
and
x - 1d faxd negative code.pdf
|
|
Thanks for filmor for identifying this.
|
|
When scaling a bitmap, currently we always scale the entire bitmap,
even if we only need a small section of the result.
This patch changes the code to take an optional 'clip' bbox, and
only scales as many pixels as are required to generate the required
output region.
|
|
|
|
Thanks to filmor's help, fix some problems where locking was going
wrong; in 2 cases we failed to unlock, and in 2 cases we tried to
free (which relocks) while already locked.
All simple fixes.
|
|
This reverts commit 08e84b18e5c1dbe8f3d32dd0aeb4b4c43debce9f.
|
|
When scaling a bitmap, currently we always scale the entire bitmap,
even if we only need a small section of the result.
This patch changes the code to take an optional 'clip' bbox, and
only scales as much of the input as as required for this output
region.
|
|
When we moved over to a context based system, we laid the foundation
for a thread-safe mupdf. This commit should complete that process.
Firstly, fz_clone_context is properly implemented so that it
makes a new context, but shares certain sections (currently
just the allocator, and the store).
Secondly, we add locking (to parts of the code that have
previously just had placeholder LOCK/UNLOCK comments). Functions
to lock and unlock a mutex are added to the allocator structure;
omit these (as is the case today) and no multithreading is
(safely) possible. The context will refuse to clone if these are
not provided.
Finally we flesh out the LOCK/UNLOCK comments to be real calls of
the functions - unfortunately this requires us to plumb fz_context
into the fz_keep_storable function (and all the fz_keep_xxx
functions that call it). This is the largest section of the patch.
No changes expected to any test files.
|
|
Some Type 3 fonts contain glyphs that rely on inheriting various
aspects of the graphics state from their calling code. (i.e. a
glyph might use d0, then fill an area without setting a color
first).
While the spec is vague on this point, we believe that technically
it is invalid. Previously mupdf defaulted all elements of the graphic
state back when beginning to draw the glyph. This does not match
what Acrobat does though, so we change the approach taken.
We now watch (by use of bits in the device flags word) for the use
of parts of the graphics state before it is set. If such use is
detected, then we note that the glyph is 'uncacheable' and render
it direct.
This seems to match Acrobats behaviour.
|
|
Automatically skip segments in a path that serve no
purpose at construction time.
* MOVE then MOVE -> the original MOVE is ignored.
* LINETO the currentpoint -> ignored if previous segment was
not a moveto.
* CURVETO the currentpoint (with coincident coords) -> ignored
if previous segment was not a moveto.
* CLOSE then CLOSE -> second close ignored.
It's worth noting here that in pdf a closepath leaves the
current point at the point which it closes to - any new
segments will begin a new subpath, but the current point
is defined.
|
|
pdf_resolve_indirect(x) = pdf_resolve_indirect(pdf_resolve_indirect(x))
now - as long as it doesn't throw an exception.
Update the rest of the code to minimise unnecessary function calls.
Previously, we were calling one function to find out if an object was
a dict, only for that to call a function to see if it needed to
resolve the object, then calling another function to actually get the
dict, only to have that call the function to check for the dict
needing resolving again!
|
|
Thanks to Zeniko for spotting these problems.
|
|
Ensure we don't get a division by zero (when *phase goes to 16).
Also ensure we don't overflow the bounds of an unsigned int.
Thanks to Zeniko for spotting these problems.
|
|
The call to opj_set_event_mgr would overwrite client_data=ctx
with client_data=stderr - not what was wanted.
Thanks to Zeniko for this.
|
|
XPS differs from PS/PDF/etc in the way it handles miters; rather than
simply converting a miter that's overly long to a bevel, it truncates
it at the miter limit. As such it needs to be handled correctly.
For clarity, expose new enumerated types for linejoins and linecaps,
and use these throughout code.
When we upgrade our freetype, we can move to using proper xps mitering
in that too.
Add new fz_matrix_max_expansion function to return a safer expansion
value that works in the case where we scale up in one direction and
down in another.
In the xps path drawing code, avoid generating unnecessary linetos.
Thanks to Zeniko for spotting these and providing implementations.
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
I don't remember exactly why I added it; but there are several
progressions when I remove it.
|
|
Keep the fuzz in just one place. Hopefully will be rendered
unnecessary by changes to make fz_bound_text accurate.
|
|
Inspired by Sumatras gdi devices need for such a function expose
the blending functions. Note that we produce unsigned char's
where Zenikos original produces ints, but it's otherwise
identical.
This requires us to make various knockon changes throughout the code
from int to unsigned char, none of which should make any difference
at all - I hope!
We reserve the right to change/amend this function in future to
operate on blocks of pixels (or pixels in different colorspaces)
(or anything else we think of) in future.
|
