Re: [GSoC] Proposal: turn git-add--interactive.perl into a builtin
On Sun, Apr 2, 2017 at 4:43 PM, Johannes Schindelin wrote: > We ask to accomplish a microproject before evaluating the proposals for > one reason: to have a good understanding how well the students would > interact with the project if they were accepted. As such, the > microprojects really are about the flow of the contribution, not to tackle > the project already. > Meaning: I would recommend staying with your microproject, in particular > if it is already in full swing. Oh, when I mentioned these bugfixes I meant I'd be willing to do those *plus* my microproject before the coding period begins as a "warm-up" to the project. I'm certainly staying with the microproject until the end! -- Daniel.
Re: [GSoC] Proposal: turn git-add--interactive.perl into a builtin
Hi Daniel, On Fri, 31 Mar 2017, Daniel Ferreira (theiostream) wrote: > Question: do you suggest any pending bugfix to git-add--interactive or > to something related that might give some useful knowledge in advance? > (for the pre-code period). My microproject involves playing with the > dir_iterator interface, which is a great exercise in code refactoring > but really does not teach me too much about Git's architecture. We ask to accomplish a microproject before evaluating the proposals for one reason: to have a good understanding how well the students would interact with the project if they were accepted. As such, the microprojects really are about the flow of the contribution, not to tackle the project already. Meaning: I would recommend staying with your microproject, in particular if it is already in full swing. Ciao, Johannes
Re: [GSoC] Proposal: turn git-add--interactive.perl into a builtin
Well, Google requires me to have a draft on a Google Doc anyway for the proposal, and I am unsure who exactly it will reach. Since it *is* part of the discussion regarding my proposal, I suppose it is worth posting here for anyone to comment: https://docs.google.com/document/d/1dvF2PNRQvvZ351jCdKzOLs7tzaDqhR7ci7TDgzYQg9I/edit?usp=sharing. -- Daniel. On Fri, Mar 31, 2017 at 2:07 AM, Daniel Ferreira (theiostream) wrote: > Hi Stefan & Johannes, > > Thank you for the precious feedback on the proposal. I don't see much > sense in sending a full "v2" of it and have you read it all over > again, so I'll just answer to your comments directly. > > Also, although the GSoC website allows me to send a "proposal draft" > to you through the website, since I've already sent it here that > shouldn't be necessary, correct? I intend to use it just to send the > final thing. > > On Wed, Mar 29, 2017 at 9:01 PM, Johannes Schindelin > wrote: >> On Tue, 28 Mar 2017, Stefan Beller wrote: >> >>> On Sat, Mar 25, 2017 at 8:15 PM, Daniel Ferreira (theiostream) >>> wrote: >>> >>> > SYNOPSIS >>> > There are many advantages to converting parts of git that are still >>> > scripts to C builtins, among which execution speed, improved >>> > compatibility and code deduplication. >>> >>> agreed. >> >> I would even add portability. But yeah, speed is a big thing. I am an >> extensive user of `git add -p` (which is backed by >> git-add--interactive.perl) and it is slow as molasses on Windows, just >> because it is a Perl script (and the Perl interpreter needs to emulate >> POSIX functionality that is frequently not even needed, such as: copying >> all memory and reopening all file descriptors in a fork() call only to >> exec() git.exe right away, tossing all of the diligently work into the >> dustbin). > > Thanks for this example – it hadn't come to my mind since I don't use > Git on Windows. I'll be sure to complement the synopsis with it. :) > >> >>> > FEASIBILITY >>> > >>> > There was only one discussion regarding the feasibility of its porting >>> > (https://public-inbox.org/git/CAP8UFD2PcBsU6=FK4OHVrB7E98ycohS_0pYcbCBar=of1hl...@mail.gmail.com/). >>> > It resulted in a consensus that doing it would be a task too large – >>> > although interesting – for GSoC 2015 based on the amount of its lines >>> > of code. It is, however, only a few lines larger than >>> > git-rebase--interactive, which has been considered an appropriate >>> > idea. As such, it looks like a possible project for three months of >>> > full-time work. >>> >>> ok, it sounds a challenging project. (currently counting 1750 lines of >>> code). Scrolling over the source code, there are quite a couple of >>> functions, where the direct equivalent in C springs to mind. >>> >>> run_cmd_pipe -> see run-command.h >>> unquote_path -> unquote_c_style ? >>> refresh -> update_index_if_able() >>> list_modified -> iterate over "const struct cache_entry *ce = >>> active_cache[i];" > > Thank you for these functions. I don't think I will be able to specify > them in detail as part of the projected timeline (e.g. "June 1: > convert calls to refresh() to use update_index_if_able()") already > because there is not enough time prior to the proposal deadline to > study their behavior in detail, and I like to avoid talking about > things I don't fully understand. Although I think I can cite them as > examples for a thesis I had put elsewhere in the proposal that "Git > APIs in Perl already have functional equivalents in C". > > Also, they will be great for my early investigation stage into > git-add--interactive. :) Once more, thanks for having listed them. > >> Yes, I think it would be more important to acquaint oneself with the >> idiosynchracies of Git's internal "API" than to get familiar with Perl: >> interpreting what obscure Perl code does is something I would gladly do as >> a mentor. > > That's really nice! I usually don't get stuck when trying to > understand code in languages I'm not too well acquainted with, but I > figured getting more familiar with Perl would speed development up. > But it does make sense that this "prior to May 4" might be better > invested learning about git's internals than Perl. > > Question: do you suggest any pending bugfix to git-add--interactive or > to something related that might give some useful knowledge in advance? > (for the pre-code period). My microproject involves playing with the > dir_iterator interface, which is a great exercise in code refactoring > but really does not teach me too much about Git's architecture. > > Even if you do not have an answer to this, I'm pretty sure I'll keep > this commitment to submitting some patch series somehow related to > git-add before GSoC begins, especially after this comment from > Johannes. > >> >>> > PROJECTED TIMELINE >>> > - Prior to May 4 >>> > -- Refine my basic knowledge of Perl >>> > -- Craft one or two small patches to some of Git's Perl components >>> > (preferentially to git-add--interactive i
Re: [GSoC] Proposal: turn git-add--interactive.perl into a builtin
Hi Stefan & Johannes, Thank you for the precious feedback on the proposal. I don't see much sense in sending a full "v2" of it and have you read it all over again, so I'll just answer to your comments directly. Also, although the GSoC website allows me to send a "proposal draft" to you through the website, since I've already sent it here that shouldn't be necessary, correct? I intend to use it just to send the final thing. On Wed, Mar 29, 2017 at 9:01 PM, Johannes Schindelin wrote: > On Tue, 28 Mar 2017, Stefan Beller wrote: > >> On Sat, Mar 25, 2017 at 8:15 PM, Daniel Ferreira (theiostream) >> wrote: >> >> > SYNOPSIS >> > There are many advantages to converting parts of git that are still >> > scripts to C builtins, among which execution speed, improved >> > compatibility and code deduplication. >> >> agreed. > > I would even add portability. But yeah, speed is a big thing. I am an > extensive user of `git add -p` (which is backed by > git-add--interactive.perl) and it is slow as molasses on Windows, just > because it is a Perl script (and the Perl interpreter needs to emulate > POSIX functionality that is frequently not even needed, such as: copying > all memory and reopening all file descriptors in a fork() call only to > exec() git.exe right away, tossing all of the diligently work into the > dustbin). Thanks for this example – it hadn't come to my mind since I don't use Git on Windows. I'll be sure to complement the synopsis with it. :) > >> > FEASIBILITY >> > >> > There was only one discussion regarding the feasibility of its porting >> > (https://public-inbox.org/git/CAP8UFD2PcBsU6=FK4OHVrB7E98ycohS_0pYcbCBar=of1hl...@mail.gmail.com/). >> > It resulted in a consensus that doing it would be a task too large – >> > although interesting – for GSoC 2015 based on the amount of its lines >> > of code. It is, however, only a few lines larger than >> > git-rebase--interactive, which has been considered an appropriate >> > idea. As such, it looks like a possible project for three months of >> > full-time work. >> >> ok, it sounds a challenging project. (currently counting 1750 lines of >> code). Scrolling over the source code, there are quite a couple of >> functions, where the direct equivalent in C springs to mind. >> >> run_cmd_pipe -> see run-command.h >> unquote_path -> unquote_c_style ? >> refresh -> update_index_if_able() >> list_modified -> iterate over "const struct cache_entry *ce = >> active_cache[i];" Thank you for these functions. I don't think I will be able to specify them in detail as part of the projected timeline (e.g. "June 1: convert calls to refresh() to use update_index_if_able()") already because there is not enough time prior to the proposal deadline to study their behavior in detail, and I like to avoid talking about things I don't fully understand. Although I think I can cite them as examples for a thesis I had put elsewhere in the proposal that "Git APIs in Perl already have functional equivalents in C". Also, they will be great for my early investigation stage into git-add--interactive. :) Once more, thanks for having listed them. > Yes, I think it would be more important to acquaint oneself with the > idiosynchracies of Git's internal "API" than to get familiar with Perl: > interpreting what obscure Perl code does is something I would gladly do as > a mentor. That's really nice! I usually don't get stuck when trying to understand code in languages I'm not too well acquainted with, but I figured getting more familiar with Perl would speed development up. But it does make sense that this "prior to May 4" might be better invested learning about git's internals than Perl. Question: do you suggest any pending bugfix to git-add--interactive or to something related that might give some useful knowledge in advance? (for the pre-code period). My microproject involves playing with the dir_iterator interface, which is a great exercise in code refactoring but really does not teach me too much about Git's architecture. Even if you do not have an answer to this, I'm pretty sure I'll keep this commitment to submitting some patch series somehow related to git-add before GSoC begins, especially after this comment from Johannes. > >> > PROJECTED TIMELINE >> > - Prior to May 4 >> > -- Refine my basic knowledge of Perl >> > -- Craft one or two small patches to some of Git's Perl components >> > (preferentially to git-add--interactive itself) to improve my >> > understanding of the language and of how Git's Perl scripts actually >> > work So yeah, I think this could be rewritten as: - Prior to May 4 -- Craft two or three small patch series to git-add--interactive or related components to improve my understanding of Git's internal architecture, especially that related to git-add. > >> > - May 4 - May 30 >> > -- Clarify implementation details with my mentor, and work on a more >> > detailed roadmap for the project >> > -- Investigate roughly how to replace command invocations from the
Re: [GSoC] Proposal: turn git-add--interactive.perl into a builtin
Hi Stefan & Daniel, On Tue, 28 Mar 2017, Stefan Beller wrote: > On Sat, Mar 25, 2017 at 8:15 PM, Daniel Ferreira (theiostream) > wrote: > > > SYNOPSIS > > There are many advantages to converting parts of git that are still > > scripts to C builtins, among which execution speed, improved > > compatibility and code deduplication. > > agreed. I would even add portability. But yeah, speed is a big thing. I am an extensive user of `git add -p` (which is backed by git-add--interactive.perl) and it is slow as molasses on Windows, just because it is a Perl script (and the Perl interpreter needs to emulate POSIX functionality that is frequently not even needed, such as: copying all memory and reopening all file descriptors in a fork() call only to exec() git.exe right away, tossing all of the diligently work into the dustbin). > > git-add--interactive, one of the most useful features of Git. > > knee jerk reaction: I never used it, so it cannot be that important ;) > (I use git-gui, which is essentially the same workflow. There are tons > of ways to accomplish a given goal using Git, so I guess we don't > want to get in an argument here). Well, I make up for your lack of `git add -i` usage. Of course, since you use git-gui, you are simply using another dependency that bloats Git for Windows: Tcl/Tk. > > FEASIBILITY > > > > There was only one discussion regarding the feasibility of its porting > > (https://public-inbox.org/git/CAP8UFD2PcBsU6=FK4OHVrB7E98ycohS_0pYcbCBar=of1hl...@mail.gmail.com/). > > It resulted in a consensus that doing it would be a task too large – > > although interesting – for GSoC 2015 based on the amount of its lines > > of code. It is, however, only a few lines larger than > > git-rebase--interactive, which has been considered an appropriate > > idea. As such, it looks like a possible project for three months of > > full-time work. > > ok, it sounds a challenging project. (currently counting 1750 lines of > code). Scrolling over the source code, there are quite a couple of > functions, where the direct equivalent in C springs to mind. > > run_cmd_pipe -> see run-command.h > unquote_path -> unquote_c_style ? > refresh -> update_index_if_able() > list_modified -> iterate over "const struct cache_entry *ce = > active_cache[i];" Yes, I think it would be more important to acquaint oneself with the idiosynchracies of Git's internal "API" than to get familiar with Perl: interpreting what obscure Perl code does is something I would gladly do as a mentor. > > PROJECTED TIMELINE > > - Prior to May 4 > > -- Refine my basic knowledge of Perl > > -- Craft one or two small patches to some of Git's Perl components > > (preferentially to git-add--interactive itself) to improve my > > understanding of the language and of how Git's Perl scripts actually > > work As I mentioned above, the Perl code should be fairly intuitive for the most part, with maybe a couple of pieces of code using more advanced Perl techniques. Given the scope of the project, I would recommend working closely together with the mentor(s) to clarify what those code parts do. > > - May 4 - May 30 > > -- Clarify implementation details with my mentor, and work on a more > > detailed roadmap for the project > > -- Investigate roughly how to replace command invocations from the > > script with actual builtin functions; which Git APIs in Perl already > > have functional equivalents in C; which parts will require a full > > rewrite. > > There are different approaches for replacing functionality in another > language. Examples: > * Implement the functionality in C and then have a "flag-day" commit > 783d7e865e (builtin-am: remove redirection to git-am.sh, 2015-08-04) > This only works when the whole functionality was replaced in prior commits > * Implement partial functionality in C and call it via a helper function. > 3604242f08 (submodule: port init from shell to C, 2016-04-15) > This works well for only partial conversions (the larger the thing to > convert the more appealing this is, as it gets code shipped early.) > When choosing this strategy, this part of the Project would be to > identify parts that could be ported on its own without much > additional glue-code. To offer my perspective: I strongly prefer the latter approach. Not only does it yield earlier results, it also makes it substantially easier to handle the project even if it should turn out to be a little larger than just 3 months. > > - May 30 - June 30 (start of coding period) > > -- Define the architecture of the builtin within git (which > > functions/interfaces will it have? where will its code reside?). > > -- Implement a small subset of the builtin (to be defined with my > > mentor) and glue it into the existing Perl script. Present this as a > > first patch to get feedback early regarding the implementation and > > avoid piling up mistakes early. > > -- Do necessary changes based on this initial review. > > -- Have roughly 1/3 of the scr
Re: [GSoC] Proposal: turn git-add--interactive.perl into a builtin
On Sat, Mar 25, 2017 at 8:15 PM, Daniel Ferreira (theiostream) wrote: > SYNOPSIS > There are many advantages to converting parts of git that are still > scripts to C builtins, among which execution speed, improved > compatibility and code deduplication. agreed. > git-add--interactive, one of the most useful features of Git. knee jerk reaction: I never used it, so it cannot be that important ;) (I use git-gui, which is essentially the same workflow. There are tons of ways to accomplish a given goal using Git, so I guess we don't want to get in an argument here). > > FEASIBILITY > > There was only one discussion regarding the feasibility of its porting > (https://public-inbox.org/git/CAP8UFD2PcBsU6=FK4OHVrB7E98ycohS_0pYcbCBar=of1hl...@mail.gmail.com/). > It resulted in a consensus that doing it would be a task too large – > although interesting – for GSoC 2015 based on the amount of its lines > of code. It is, however, only a few lines larger than > git-rebase--interactive, which has been considered an appropriate > idea. As such, it looks like a possible project for three months of > full-time work. ok, it sounds a challenging project. (currently counting 1750 lines of code). Scrolling over the source code, there are quite a couple of functions, where the direct equivalent in C springs to mind. run_cmd_pipe -> see run-command.h unquote_path -> unquote_c_style ? refresh -> update_index_if_able() list_modified -> iterate over "const struct cache_entry *ce = active_cache[i];" > PROJECTED TIMELINE > - Prior to May 4 > -- Refine my basic knowledge of Perl > -- Craft one or two small patches to some of Git's Perl components > (preferentially to git-add--interactive itself) to improve my > understanding of the language and of how Git's Perl scripts actually > work > > - May 4 - May 30 > -- Clarify implementation details with my mentor, and work on a more > detailed roadmap for the project > -- Investigate roughly how to replace command invocations from the > script with actual builtin functions; which Git APIs in Perl already > have functional equivalents in C; which parts will require a full > rewrite. There are different approaches for replacing functionality in another language. Examples: * Implement the functionality in C and then have a "flag-day" commit 783d7e865e (builtin-am: remove redirection to git-am.sh, 2015-08-04) This only works when the whole functionality was replaced in prior commits * Implement partial functionality in C and call it via a helper function. 3604242f08 (submodule: port init from shell to C, 2016-04-15) This works well for only partial conversions (the larger the thing to convert the more appealing this is, as it gets code shipped early.) When choosing this strategy, this part of the Project would be to identify parts that could be ported on its own without much additional glue-code. > - May 30 - June 30 (start of coding period) > -- Define the architecture of the builtin within git (which > functions/interfaces will it have? where will its code reside?). > -- Implement a small subset of the builtin (to be defined with my > mentor) and glue it into the existing Perl script. Present this as a > first patch to get feedback early regarding the implementation and > avoid piling up mistakes early. > -- Do necessary changes based on this initial review. > -- Have roughly 1/3 of the script's functionality ported to C. > > - June 30 - July 28 > -- Port the remainder of the script to a builtin. > -- Have a weekly roadmap, sending a part of the patch every 15 days to > the mailing list for review and to avoid massive commits by the end of > GSoC. yeah; send early, send often. ;) > -- Apply suggestions from community reviews when possible; if not, > save them for doing toward the end of GSoC (see below). Please do not underestimate the discussion by community, finding consensus on list consumes a bit of time in some cases. > (Note: due to a previous commitment, during a five-day period of July > I will only be able to work part-time on GSoC. The actual week will be > known over the next weeks.) Maybe you want to shift the schedule up to here by one week then? (e.g. the first period would be April 27 - May 23) > > - July 28 - August 29 > -- By the start of this period, send a patch with the builtin fully > implemented to the mailing list. /a patch/a patch series consisting of many patches/ Experience shows that smaller patches are easier to review as it is more focused. Consider e.g. e86ab2c1cd (wt-status: convert to struct object_id, 2017-02-21) and the parents leading up to this commit. They work on the same big topic, but focus on very regional areas to ease review. > -- Fix bugs, test extensively, possibly extend test coverage for > git-add--interactive. AFAICT ('$ git grep "git add -i"') there is only t3701 testing the interactive add. Maybe we need to add tests first to document current behavior, before attempting a conversion? This could go well i
[GSoC] Proposal: turn git-add--interactive.perl into a builtin
Hi there. First of all, I'd like to thank all of the support up to now with my microproject :). Here's a first draft of my proposal for Google Summer of Code '17, based on the "Convert scripts to builtins" idea. Please let me know what you think. --- SYNOPSIS There are many advantages to converting parts of git that are still scripts to C builtins, among which execution speed, improved compatibility and code deduplication. This proposal aims to apply this to git-add--interactive, one of the most useful features of Git. FEASIBILITY Many git scripts have attracted attention for being turned into builtins. There is ongoing work on git-stash (https://public-inbox.org/git/20170321053135.thk77soxc4irx...@sigill.intra.peff.net/), and porting interactive rebase is one of the ideas for this edition of GSoC. Not as much attention, however, has been directed to git-add--interactive. There was only one discussion regarding the feasibility of its porting (https://public-inbox.org/git/CAP8UFD2PcBsU6=FK4OHVrB7E98ycohS_0pYcbCBar=of1hl...@mail.gmail.com/). It resulted in a consensus that doing it would be a task too large – although interesting – for GSoC 2015 based on the amount of its lines of code. It is, however, only a few lines larger than git-rebase--interactive, which has been considered an appropriate idea. As such, it looks like a possible project for three months of full-time work. Aside from the benefits cited above, turning git-add--interactive into a builtin can reduce Git's dependency on Perl to the point where no "common" command would continue to rely on it. PROJECTED TIMELINE - Prior to May 4 -- Refine my basic knowledge of Perl -- Craft one or two small patches to some of Git's Perl components (preferentially to git-add--interactive itself) to improve my understanding of the language and of how Git's Perl scripts actually work - May 4 - May 30 -- Clarify implementation details with my mentor, and work on a more detailed roadmap for the project -- Investigate roughly how to replace command invocations from the script with actual builtin functions; which Git APIs in Perl already have functional equivalents in C; which parts will require a full rewrite. - May 30 - June 30 (start of coding period) -- Define the architecture of the builtin within git (which functions/interfaces will it have? where will its code reside?). -- Implement a small subset of the builtin (to be defined with my mentor) and glue it into the existing Perl script. Present this as a first patch to get feedback early regarding the implementation and avoid piling up mistakes early. -- Do necessary changes based on this initial review. -- Have roughly 1/3 of the script's functionality ported to C. - June 30 - July 28 -- Port the remainder of the script to a builtin. -- Have a weekly roadmap, sending a part of the patch every 15 days to the mailing list for review and to avoid massive commits by the end of GSoC. -- Apply suggestions from community reviews when possible; if not, save them for doing toward the end of GSoC (see below). (Note: due to a previous commitment, during a five-day period of July I will only be able to work part-time on GSoC. The actual week will be known over the next weeks.) - July 28 - August 29 -- By the start of this period, send a patch with the builtin fully implemented to the mailing list. -- Fix bugs, test extensively, possibly extend test coverage for git-add--interactive. -- Respond to the (predictably big) community feedback regarding the change. I currently work full-time in a payments company (see below), but in case of being accepted I am willing to quit my job some months early to dedicate myself fully to GSoC starting June. BIOGRAPHICAL INFORMATION My name is Daniel Ferreira and I'm a student from São Paulo, Brazil. I was accepted by Stanford University last year and I will start college this fall. I started coding C about six years ago writing up system modifications ("tweaks") for jailbroken iPhones. Since then, I have written/contributed to a couple of open-source projects like an IRC bot and other assorted things – all of them tracked on Git (https://github.com/theiostream). I have also developed a (closed-source) library in C for interacting with payment terminals in the company I have worked for over the last two years (Pagar.me). There, we use Git extensively for managing projects with around 20 people working concurrently. MICROPROJECT I have sent a series of patches to complete the microproject of converting recursive calls to readdir() into calls to dir_iterator. The most recent version can be found in https://public-inbox.org/git/1490465551-71056-2-git-send-email-bnm...@gmail.com/T/#u. Thanks, -- Daniel.