El diumenge, 28 de gener de 2018, a les 13:24:45 CET, suzuki toshiya va escriure: > Dear Albert, > > > As far as i can see we don't use exceptions anywhere in the poppler code, > > so i would not introduce them "just for this". > > Oh, I'm sorry for my overlooking that. Here is updated patch which checks > out-of-bound value to char_bbox() and return rect(0,0,0,0) if bad index > is passed. Also I changed the type of the index from int to size_t.
Can you please try adding some documentation in the cpp file like the other functions have? Cheers, Albert > > Regards, > mpsuzuki > > Albert Astals Cid wrote: > > El dissabte, 27 de gener de 2018, a les 17:17:37 CET, suzuki toshiya va > > > > escriure: > >> Dear Albert, > >> > >> Oops, I apologize that I overlooked your response to > >> improve the patch. > >> > >>> You have one text_box where you have 17 char bboxes but the > >>> ustr.to_utf8().size() is 27, so if you iterate it's easy to get a crash > >>> because you get an out of bounds. > >> > >> Indeed, it might be common scenarios for the > >> programmers assuming the input as ASCII data but > >> something different is given. > >> > >>> So it would be nice to make > >>> rectf char_bbox(int i) const; > >>> not crash on an invalid i, i guess return a 0x0 rect > >>> and then probably add some documentation about it? > >> > >> Checking the features of C++ std::vector, I think > >> we have 2 options: > >> > >> a) use (as current patch) m_data->char_bbox[i] and > >> sanitize the i-index before using it (as you proposed), > >> and the bad values cause 0x0 rectf. > >> > >> b) use m_data->char_bbox.at(i) and let stdlib raise > >> std::out_of_range error. > >> > >> which is better for C++ programmers? > > > > As far as i can see we don't use exceptions anywhere in the poppler code, > > so i would not introduce them "just for this". > > > > Cheers, > > > > Albert > > > >>> FWIW this was a real problem in Okular and i fixed it with > >>> https://cgit.kde.org/okular.git/commit/generators/poppler/generator_pdf. > >>> cp > >>> p?id=dcf0e78227959a52300d8f253c4b1058b3e81567 > >>> > >>> Am i making any sense here? > >> > >> Thank you very much for the important suggestion and > >> sorry for delayed reponse! > >> > >> Regards, > >> mpsuzuki > >> > >> Albert Astals Cid wrote: > >>> El dimecres, 3 de gener de 2018, a les 21:10:06 CET, Adam Reichold va > > > > escriure: > >>>> Hello mpsuzuki, > >>>> > >>>> I do not think you need the two indirections: Since you want to keep > >>>> that m_data indirection for ABI compatibility, just return > >>>> std::vector<text_box> as text_box basically "is" a unique_ptr to its > >>>> data with the additional getter methods. (You just need to make sure to > >>>> default the move constructor and assignment operator since no copying > >>>> implies no moving by default.) > >>>> > >>>> Attached is an update patch along those lines. (I also took the liberty > >>>> to replace some bare deletes by use of unique_ptr in the implementation > >>>> of page::text_list as well.) > >>> > >>> One thing that i wanted to improve in the Qt5 frontend but never go to, > >>> maybe we can start here is the fact that the number of boxes is "a bit > >>> random", for example take https://bugs.kde.org/attachment.cgi?id=66189 > >>> > >>> You have one text_box where you have 17 char bboxes but the > >>> ustr.to_utf8().size() is 27, so if you iterate it's easy to get a crash > >>> because you get an out of bounds. > >>> > >>> So it would be nice to make > >>> rectf char_bbox(int i) const; > >>> not crash on an invalid i, i guess return a 0x0 rect > >>> and then probably add some documentation about it? > >>> > >>> FWIW this was a real problem in Okular and i fixed it with > >>> https://cgit.kde.org/okular.git/commit/generators/poppler/generator_pdf. > >>> cp > >>> p?id=dcf0e78227959a52300d8f253c4b1058b3e81567 > >>> > >>> Am i making any sense here? > >>> > >>> Cheers, > >>> > >>> Albert > >>>> > >>>> Best regards, Adam. > >>>> > >>>> Am 03.01.2018 um 07:38 schrieb suzuki toshiya: > >>>>> Dear Adam, > >>>>> > >>>>> Thank you for the technical information on the difference of > >>>>> std::shared_ptr and std::unique_ptr. Just I've tried to replace > >>>>> the vector of the pointers to that of the unique_ptrs, and > >>>>> remove the next_xxx methods. > >>>>> > >>>>> I attached the revised patch (gzipped) to the master, and > >>>>> here I quote the revised part from my last revision, for > >>>>> convenience to take a look on it. > >>>>> > >>>>> Regards, > >>>>> mpsuzuki > >>>>> > >>>>> diff --git a/cpp/poppler-private.h b/cpp/poppler-private.h > >>>>> index 726068a..2cedd1e 100644 > >>>>> --- a/cpp/poppler-private.h > >>>>> +++ b/cpp/poppler-private.h > >>>>> @@ -72,12 +72,11 @@ class text_box_data > >>>>> > >>>>> { > >>>>> > >>>>> public: > >>>>> text_box_data() > >>>>> > >>>>> - : next_text_box(0), has_space_after(false) > >>>>> + : has_space_after(false) > >>>>> > >>>>> { > >>>>> } > >>>>> ustring text; > >>>>> rectf bbox; > >>>>> > >>>>> - text_box *next_text_box; > >>>>> > >>>>> std::vector<rectf> char_bboxes; > >>>>> bool has_space_after; > >>>>> > >>>>> }; > >>>>> > >>>>> diff --git a/cpp/poppler-page.h b/cpp/poppler-page.h > >>>>> index 18af213..3013997 100644 > >>>>> --- a/cpp/poppler-page.h > >>>>> +++ b/cpp/poppler-page.h > >>>>> @@ -22,6 +22,8 @@ > >>>>> > >>>>> #include "poppler-global.h" > >>>>> #include "poppler-rectangle.h" > >>>>> > >>>>> +#include <memory> > >>>>> + > >>>>> > >>>>> namespace poppler > >>>>> { > >>>>> > >>>>> @@ -33,12 +35,10 @@ class POPPLER_CPP_EXPORT text_box { > >>>>> > >>>>> ~text_box(); > >>>>> ustring text() const; > >>>>> rectf bbox() const; > >>>>> > >>>>> - text_box *next_text_box() const; > >>>>> - text_box *next_word() { return this->next_text_box(); }; > >>>>> > >>>>> rectf char_bbox(int i) const; > >>>>> bool has_space_after() const; > >>>>> > >>>>> private: > >>>>> - text_box_data* m_data; > >>>>> + std::unique_ptr<text_box_data> m_data; > >>>>> > >>>>> }; > >>>>> > >>>>> class document; > >>>>> > >>>>> @@ -79,7 +79,7 @@ public: > >>>>> ustring text(const rectf &rect = rectf()) const; > >>>>> ustring text(const rectf &rect, text_layout_enum layout_mode) > >>>>> const; > >>>>> > >>>>> - std::vector<text_box*> text_list(rotation_enum rotation) const; > >>>>> + std::vector<std::unique_ptr<text_box>> text_list(rotation_enum > >>>>> rotation) const;> > >>>>> > >>>>> private: > >>>>> page(document_private *doc, int index); > >>>>> > >>>>> diff --git a/cpp/poppler-page.cpp b/cpp/poppler-page.cpp > >>>>> index 9461ab9..5da2e1d 100644 > >>>>> --- a/cpp/poppler-page.cpp > >>>>> +++ b/cpp/poppler-page.cpp > >>>>> @@ -291,14 +291,13 @@ ustring page::text(const rectf &r, > >>>>> text_layout_enum > >>>>> layout_mode) const > >>>>> > >>>>> */ > >>>>> > >>>>> text_box::text_box(const ustring& text, const rectf &bbox) > >>>>> { > >>>>> > >>>>> - m_data = new text_box_data(); > >>>>> + m_data = std::unique_ptr<text_box_data>(new text_box_data()); > >>>>> > >>>>> m_data->text = text; > >>>>> m_data->bbox = bbox; > >>>>> > >>>>> } > >>>>> > >>>>> text_box::~text_box() > >>>>> { > >>>>> > >>>>> - delete m_data; > >>>>> > >>>>> } > >>>>> > >>>>> ustring text_box::text() const > >>>>> > >>>>> @@ -311,11 +310,6 @@ rectf text_box::bbox() const > >>>>> > >>>>> return m_data->bbox; > >>>>> > >>>>> } > >>>>> > >>>>> -text_box* text_box::next_text_box() const > >>>>> -{ > >>>>> - return m_data->next_text_box; > >>>>> -} > >>>>> - > >>>>> > >>>>> rectf text_box::char_bbox(int i) const > >>>>> { > >>>>> > >>>>> return m_data->char_bboxes[i]; > >>>>> > >>>>> @@ -326,10 +320,10 @@ bool text_box::has_space_after() const > >>>>> > >>>>> return m_data->has_space_after; > >>>>> > >>>>> } > >>>>> > >>>>> -std::vector<text_box*> page::text_list(rotation_enum rotate) const > >>>>> +std::vector<std::unique_ptr<text_box>> page::text_list(rotation_enum > >>>>> rotate) const> > >>>>> > >>>>> { > >>>>> > >>>>> TextOutputDev *output_dev; > >>>>> > >>>>> - std::vector<text_box*> output_list; > >>>>> + std::vector<std::unique_ptr<text_box>> output_list; > >>>>> > >>>>> const int rotation_value = (int)rotate * 90; > >>>>> > >>>>> /* config values are same with Qt5 Page::TextList() */ > >>>>> > >>>>> @@ -366,7 +360,7 @@ std::vector<text_box*> > >>>>> page::text_list(rotation_enum > >>>>> rotate) const > >>>>> > >>>>> double xMin, yMin, xMax, yMax; > >>>>> word->getBBox(&xMin, &yMin, &xMax, &yMax); > >>>>> > >>>>> - text_box* tb = new text_box(ustr, rectf(xMin, yMin, xMax-xMin, > >>>>> yMax-yMin)); + std::unique_ptr<text_box> tb = > >>>>> std::unique_ptr<text_box>(new text_box(ustr, rectf(xMin, yMin, > >>>>> xMax-xMin, > >>>>> yMax-yMin))); > >>>>> > >>>>> tb->m_data->has_space_after = (word->hasSpaceAfter() == gTrue); > >>>>> > >>>>> tb->m_data->char_bboxes.reserve(word->getLength()); > >>>>> > >>>>> @@ -375,10 +369,7 @@ std::vector<text_box*> > >>>>> page::text_list(rotation_enum > >>>>> rotate) const > >>>>> > >>>>> tb->m_data->char_bboxes.push_back(rectf(xMin, yMin, xMax- xMin, > >>>>> yMax-yMin)); > >>>>> > >>>>> } > >>>>> > >>>>> - if (output_list.size() > 0) > >>>>> - output_list.back()->m_data->next_text_box = tb; > >>>>> - > >>>>> - output_list.push_back(tb); > >>>>> + output_list.push_back(std::move(tb)); > >>>>> > >>>>> } > >>>>> delete word_list; > >>>>> delete output_dev; > >>>>> > >>>>> diff --git a/cpp/tests/poppler-dump.cpp b/cpp/tests/poppler-dump.cpp > >>>>> index 09b180d..d26a0ef 100644 > >>>>> --- a/cpp/tests/poppler-dump.cpp > >>>>> +++ b/cpp/tests/poppler-dump.cpp > >>>>> @@ -333,7 +333,7 @@ static void print_page_text_list(poppler::page *p) > >>>>> > >>>>> std::cout << std::endl; > >>>>> return; > >>>>> > >>>>> } > >>>>> > >>>>> - std::vector<poppler::text_box*> text_list = > >>>>> p->text_list(poppler::rotate_0); + > >>>>> std::vector<std::unique_ptr<poppler::text_box>> text_list = > >>>>> p->text_list(poppler::rotate_0); > >>>>> > >>>>> std::cout << "---" << std::endl; > >>>>> for (size_t i = 0; i < text_list.size(); i ++) { > >>>>> > >>>>> @@ -343,7 +343,6 @@ static void print_page_text_list(poppler::page *p) > >>>>> > >>>>> std::cout << "( x=" << bbox.x() << " y=" << bbox.y() << " w=" > >>>>> << > >>>>> > >>>>> bbox.width() << " h=" << bbox.height() << " )"; > >>>>> > >>>>> std::cout << std::endl; > >>>>> > >>>>> - delete text_list[i]; > >>>>> > >>>>> } > >>>>> std::cout << "---" << std::endl; > >>>>> > >>>>> } > >>>>> > >>>>> Adam Reichold wrote: > >>>>>> Hello mpsuzuki, > >>>>>> > >>>>>> std::shared_ptr was introduced in C++11 and Poppler does use C++11 > >>>>>> only > >>>>>> since a relatively short time, so I guess there just was no time to > >>>>>> use > >>>>>> it anywhere. > >>>>>> > >>>>>> In any case it is a pretty heavy-handed solution due to the atomic > >>>>>> memory accesses on the reference counter which will slow down even > >>>>>> single-threaded programs which do not need it. Hence I would suggest > >>>>>> starting with std::unique_ptr to get a move-only type. > >>>>>> > >>>>>> Best regards, Adam. > >>>>>> > >>>>>> Am 02.01.2018 um 08:19 schrieb suzuki toshiya: > >>>>>>> Dear Albert, Adam, > >>>>>>> > >>>>>>> Thank you for the helpful review. I should have more > >>>>>>> training on C++... Please let me spend to improve the > >>>>>>> patch. > >>>>>>> > >>>>>>>> (Another easy option albeit with some > >>>>>>>> overhead to get automatic destruction would be to wrap the actual > >>>>>>>> data > >>>>>>>> inside a std::shared_ptr and hence use reference counting.) > >>>>>>> > >>>>>>> Yeah, from some posts in stackoverflow, I found about > >>>>>>> shared_ptr... But it seems that current poppler does > >>>>>>> not use shared_ptr at all. Is this a coding policy? > >>>>>>> > >>>>>>> Regards, > >>>>>>> mpsuzuki > >>>>>>> > >>>>>>> Adam Reichold wrote: > >>>>>>>> Hello > >>>>>>>> > >>>>>>>> Am 02.01.2018 um 01:06 schrieb Albert Astals Cid: > >>>>>>>>> El diumenge, 31 de desembre de 2017, a les 0:45:16 CET, suzuki > >>>>>>>>> toshiya > >>>>>>>>> va > >>>>>>>>> > >>>>>>>>> escriure: > >>>>>>>>>> Hi, > >>>>>>>>>> > >>>>>>>>>> I've tried to implement the suggestion, I attached my current > >>>>>>>>>> patch. > >>>>>>>>>> > >>>>>>>>>> As suggested, the most part is just copied from Qt frontend and > >>>>>>>>>> renamed, > >>>>>>>>>> except of one point: TextBox.nextWord() looks slightly confusing, > >>>>>>>>>> because the returned object is a pointer to TextBox. I wrote > >>>>>>>>>> text_box.next_text_box() and a macro text_box.next_word() which > >>>>>>>>>> calls next_text_box() internally. > >>>>>>>>>> > >>>>>>>>>> Another point I want to discuss is the design of the list give by > >>>>>>>>>> poppler::page::text_list(). In Qt frontend, Page::textList() > >>>>>>>>>> returns > >>>>>>>>>> QList<TextBox*>. For similarity, current patch returns > >>>>>>>>>> std::vector<text_box*> for similarity to Qt frontend. > >>>>>>>>>> > >>>>>>>>>> But, if we return the vector of pointers, the client should > >>>>>>>>>> destruct > >>>>>>>>>> the objects pointed by the vector, before destructing vector > >>>>>>>>>> itself. > >>>>>>>>>> Using a vector of text_box (not the pointer but the object > >>>>>>>>>> itself), > >>>>>>>>>> like std::vector<text_box>, could be better, because the > >>>>>>>>>> destructor > >>>>>>>>>> of the vector would internally call the destructor for text_box > >>>>>>>>>> object. > >>>>>>>>>> (Qt has qDeleteAll(), but I think std::vector does not have > >>>>>>>>>> such). > >>>>>>>>>> If I'm misunderstanding about C++, please correct. > >>>>>>>>> > >>>>>>>>> First you need to fix the text_box class, you either need to make > >>>>>>>>> it > >>>>>>>>> uncopiable (and thus making your suggestion not possible) or you > >>>>>>>>> need > >>>>>>>>> to make the copy and assignment operators not break your class > >>>>>>>>> since > >>>>>>>>> at the moment the default operators will just copy the pointer and > >>>>>>>>> everything will break because you will end up with a dangling > >>>>>>>>> pointer. > >>>>>>>>> > >>>>>>>>> If you go for the second option you'll want the move constructor > >>>>>>>>> and > >>>>>>>>> move > >>>>>>>>> operator too. > >>>>>>>> > >>>>>>>> Should the first option also be viable if text_box becomes a > >>>>>>>> move-only > >>>>>>>> type, i.e. no copying but move construction and assignment? I think > >>>>>>>> std::vector can handle it. (Another easy option albeit with some > >>>>>>>> overhead to get automatic destruction would be to wrap the actual > >>>>>>>> data > >>>>>>>> inside a std::shared_ptr and hence use reference counting.) > >>>>>>>> > >>>>>>>> Best regards, Adam. > >>>>>>>> > >>>>>>>>> Cheers, > >>>>>>>>> > >>>>>>>>> Albert > >>>>>>>>>> > >>>>>>>>>> Regards, > >>>>>>>>>> mpsuzuki > >>>>>>>>>> > >>>>>>>>>> Albert Astals Cid wrote: > >>>>>>>>>>> El dimecres, 27 de desembre de 2017, a les 12:26:25 CET, Jeroen > >>>>>>>>>>> Ooms > >>>>>>>>>>> va > >>>>>>>>>>> > >>>>>>>>>>> escriure: > >>>>>>>>>>>> Is there a method in poppler-cpp to extract text from a pdf > >>>>>>>>>>>> document, > >>>>>>>>>>>> including the position of each text box? Currently we use > >>>>>>>>>>>> page->text() > >>>>>>>>>>>> with page::physical_layout which gives all text per page, but I > >>>>>>>>>>>> need > >>>>>>>>>>>> more detailed information about each text box per page. > >>>>>>>>>>> > >>>>>>>>>>> You want to code the variant of qt5 frontend > >>>>>>>>>>> Poppler::Page::textList() for > >>>>>>>>>>> cpp frontend, it shouldn't be that hard getting inspiration > >>>>>>>>>>> (i.e. > >>>>>>>>>>> almost-copying) the code, do you have time for it? > >>>>>>>>>>> > >>>>>>>>>>> Cheers, > >>>>>>>>>>> > >>>>>>>>>>> Albert > >>>>>>>>>>>> > >>>>>>>>>>>> _______________________________________________ > >>>>>>>>>>>> poppler mailing list > >>>>>>>>>>>> poppler@lists.freedesktop.org > >>>>>>>>>>>> https://lists.freedesktop.org/mailman/listinfo/poppler > >>>>>>>>>>> > >>>>>>>>>>> _______________________________________________ > >>>>>>>>>>> poppler mailing list > >>>>>>>>>>> poppler@lists.freedesktop.org > >>>>>>>>>>> https://lists.freedesktop.org/mailman/listinfo/poppler > >>>>>>>>> > >>>>>>>>> _______________________________________________ > >>>>>>>>> poppler mailing list > >>>>>>>>> poppler@lists.freedesktop.org > >>>>>>>>> https://lists.freedesktop.org/mailman/listinfo/poppler _______________________________________________ poppler mailing list poppler@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/poppler