diff options
Diffstat (limited to 'Documentation/technical')
| -rw-r--r-- | Documentation/technical/api-allocation-growing.txt | 14 | ||||
| -rw-r--r-- | Documentation/technical/api-builtin.txt | 4 | ||||
| -rw-r--r-- | Documentation/technical/api-command.txt | 99 | ||||
| -rw-r--r-- | Documentation/technical/api-config.txt | 10 | ||||
| -rw-r--r-- | Documentation/technical/api-credentials.txt | 20 | ||||
| -rw-r--r-- | Documentation/technical/api-directory-listing.txt | 37 | ||||
| -rw-r--r-- | Documentation/technical/api-history-graph.txt | 10 | ||||
| -rw-r--r-- | Documentation/technical/api-index-skel.txt | 6 | ||||
| -rw-r--r-- | Documentation/technical/api-parse-options.txt | 2 | ||||
| -rw-r--r-- | Documentation/technical/api-remote.txt | 4 | ||||
| -rw-r--r-- | Documentation/technical/api-run-command.txt | 6 | ||||
| -rw-r--r-- | Documentation/technical/api-strbuf.txt | 10 | ||||
| -rw-r--r-- | Documentation/technical/api-string-list.txt | 8 | ||||
| -rw-r--r-- | Documentation/technical/index-format.txt | 13 | ||||
| -rw-r--r-- | Documentation/technical/pack-format.txt | 4 | ||||
| -rw-r--r-- | Documentation/technical/pack-heuristics.txt | 20 | ||||
| -rw-r--r-- | Documentation/technical/racy-git.txt | 26 | ||||
| -rw-r--r-- | Documentation/technical/shallow.txt | 3 |
18 files changed, 104 insertions, 192 deletions
diff --git a/Documentation/technical/api-allocation-growing.txt b/Documentation/technical/api-allocation-growing.txt index 43dbe09f73..542946b1ba 100644 --- a/Documentation/technical/api-allocation-growing.txt +++ b/Documentation/technical/api-allocation-growing.txt @@ -5,7 +5,9 @@ Dynamically growing an array using realloc() is error prone and boring. Define your array with: -* a pointer (`ary`) that points at the array, initialized to `NULL`; +* a pointer (`item`) that points at the array, initialized to `NULL` + (although please name the variable based on its contents, not on its + type); * an integer variable (`alloc`) that keeps track of how big the current allocation is, initialized to `0`; @@ -13,22 +15,22 @@ Define your array with: * another integer variable (`nr`) to keep track of how many elements the array currently has, initialized to `0`. -Then before adding `n`th element to the array, call `ALLOC_GROW(ary, n, +Then before adding `n`th element to the item, call `ALLOC_GROW(item, n, alloc)`. This ensures that the array can hold at least `n` elements by calling `realloc(3)` and adjusting `alloc` variable. ------------ -sometype *ary; +sometype *item; size_t nr; size_t alloc for (i = 0; i < nr; i++) - if (we like ary[i] already) + if (we like item[i] already) return; /* we did not like any existing one, so add one */ -ALLOC_GROW(ary, nr + 1, alloc); -ary[nr++] = value you like; +ALLOC_GROW(item, nr + 1, alloc); +item[nr++] = value you like; ------------ You are responsible for updating the `nr` variable. diff --git a/Documentation/technical/api-builtin.txt b/Documentation/technical/api-builtin.txt index b0cafe87be..4a4228b896 100644 --- a/Documentation/technical/api-builtin.txt +++ b/Documentation/technical/api-builtin.txt @@ -5,7 +5,7 @@ Adding a new built-in --------------------- There are 4 things to do to add a built-in command implementation to -git: +Git: . Define the implementation of the built-in command `foo` with signature: @@ -23,7 +23,7 @@ where options is the bitwise-or of: `RUN_SETUP`:: - Make sure there is a git directory to work on, and if there is a + Make sure there is a Git directory to work on, and if there is a work tree, chdir to the top of it if the command was invoked in a subdirectory. If there is no work tree, no chdir() is done. diff --git a/Documentation/technical/api-command.txt b/Documentation/technical/api-command.txt deleted file mode 100644 index d3b978177b..0000000000 --- a/Documentation/technical/api-command.txt +++ /dev/null @@ -1,99 +0,0 @@ -Integrating new subcommands -=========================== - -This is how-to documentation for people who want to add extension -commands to git. It should be read alongside api-builtin.txt. - -Runtime environment -------------------- - -git subcommands are standalone executables that live in the git exec -path, normally /usr/lib/git-core. The git executable itself is a -thin wrapper that knows where the subcommands live, and runs them by -passing command-line arguments to them. - -(If "git foo" is not found in the git exec path, the wrapper -will look in the rest of your $PATH for it. Thus, it's possible -to write local git extensions that don't live in system space.) - -Implementation languages ------------------------- - -Most subcommands are written in C or shell. A few are written in -Perl. - -While we strongly encourage coding in portable C for portability, -these specific scripting languages are also acceptable. We won't -accept more without a very strong technical case, as we don't want -to broaden the git suite's required dependencies. Import utilities, -surgical tools, remote helpers and other code at the edges of the -git suite are more lenient and we allow Python (and even Tcl/tk), -but they should not be used for core functions. - -This may change in the future. Especially Python is not allowed in -core because we need better Python integration in the git Windows -installer before we can be confident people in that environment -won't experience an unacceptably large loss of capability. - -C commands are normally written as single modules, named after the -command, that link a collection of functions called libgit. Thus, -your command 'git-foo' would normally be implemented as a single -"git-foo.c" (or "builtin/foo.c" if it is to be linked to the main -binary); this organization makes it easy for people reading the code -to find things. - -See the CodingGuidelines document for other guidance on what we consider -good practice in C and shell, and api-builtin.txt for the support -functions available to built-in commands written in C. - -What every extension command needs ----------------------------------- - -You must have a man page, written in asciidoc (this is what git help -followed by your subcommand name will display). Be aware that there is -a local asciidoc configuration and macros which you should use. It's -often helpful to start by cloning an existing page and replacing the -text content. - -You must have a test, written to report in TAP (Test Anything Protocol). -Tests are executables (usually shell scripts) that live in the 't' -subdirectory of the tree. Each test name begins with 't' and a sequence -number that controls where in the test sequence it will be executed; -conventionally the rest of the name stem is that of the command -being tested. - -Read the file t/README to learn more about the conventions to be used -in writing tests, and the test support library. - -Integrating a command ---------------------- - -Here are the things you need to do when you want to merge a new -subcommand into the git tree. - -1. Don't forget to sign off your patch! - -2. Append your command name to one of the variables BUILTIN_OBJS, -EXTRA_PROGRAMS, SCRIPT_SH, SCRIPT_PERL or SCRIPT_PYTHON. - -3. Drop its test in the t directory. - -4. If your command is implemented in an interpreted language with a -p-code intermediate form, make sure .gitignore in the main directory -includes a pattern entry that ignores such files. Python .pyc and -.pyo files will already be covered. - -5. If your command has any dependency on a particular version of -your language, document it in the INSTALL file. - -6. There is a file command-list.txt in the distribution main directory -that categorizes commands by type, so they can be listed in appropriate -subsections in the documentation's summary command list. Add an entry -for yours. To understand the categories, look at git-cmmands.txt -in the main directory. - -7. Give the maintainer one paragraph to include in the RelNotes file -to describe the new feature; a good place to do so is in the cover -letter [PATCH 0/n]. - -That's all there is to it. diff --git a/Documentation/technical/api-config.txt b/Documentation/technical/api-config.txt index edf8dfb99b..230b3a0f60 100644 --- a/Documentation/technical/api-config.txt +++ b/Documentation/technical/api-config.txt @@ -1,7 +1,7 @@ config API ========== -The config API gives callers a way to access git configuration files +The config API gives callers a way to access Git configuration files (and files which have the same syntax). See linkgit:git-config[1] for a discussion of the config file syntax. @@ -12,7 +12,7 @@ Config files are parsed linearly, and each variable found is passed to a caller-provided callback function. The callback function is responsible for any actions to be taken on the config option, and is free to ignore some options. It is not uncommon for the configuration to be parsed -several times during the run of a git program, with different callbacks +several times during the run of a Git program, with different callbacks picking out different variables useful to themselves. A config callback function takes three parameters: @@ -36,7 +36,7 @@ Basic Config Querying --------------------- Most programs will simply want to look up variables in all config files -that git knows about, using the normal precedence rules. To do this, +that Git knows about, using the normal precedence rules. To do this, call `git_config` with a callback function and void data pointer. `git_config` will read all config sources in order of increasing @@ -49,7 +49,7 @@ value is left at the end). The `git_config_with_options` function lets the caller examine config while adjusting some of the default behavior of `git_config`. It should -almost never be used by "regular" git code that is looking up +almost never be used by "regular" Git code that is looking up configuration variables. It is intended for advanced callers like `git-config`, which are intentionally tweaking the normal config-lookup process. It takes two extra parameters: @@ -66,7 +66,7 @@ Regular `git_config` defaults to `1`. There is a special version of `git_config` called `git_config_early`. This version takes an additional parameter to specify the repository config, instead of having it looked up via `git_path`. This is useful -early in a git program before the repository has been found. Unless +early in a Git program before the repository has been found. Unless you're working with early setup code, you probably don't want to use this. diff --git a/Documentation/technical/api-credentials.txt b/Documentation/technical/api-credentials.txt index 5977b58e57..516fda7412 100644 --- a/Documentation/technical/api-credentials.txt +++ b/Documentation/technical/api-credentials.txt @@ -7,9 +7,9 @@ world can take many forms, in this document the word "credential" always refers to a username and password pair). This document describes two interfaces: the C API that the credential -subsystem provides to the rest of git, and the protocol that git uses to +subsystem provides to the rest of Git, and the protocol that Git uses to communicate with system-specific "credential helpers". If you are -writing git code that wants to look up or prompt for credentials, see +writing Git code that wants to look up or prompt for credentials, see the section "C API" below. If you want to write your own helper, see the section on "Credential Helpers" below. @@ -18,7 +18,7 @@ Typical setup ------------ +-----------------------+ -| git code (C) |--- to server requiring ---> +| Git code (C) |--- to server requiring ---> | | authentication |.......................| | C credential API |--- prompt ---> User @@ -27,11 +27,11 @@ Typical setup | pipe | | v +-----------------------+ -| git credential helper | +| Git credential helper | +-----------------------+ ------------ -The git code (typically a remote-helper) will call the C API to obtain +The Git code (typically a remote-helper) will call the C API to obtain credential data like a login/password pair (credential_fill). The API will itself call a remote helper (e.g. "git credential-cache" or "git credential-store") that may retrieve credential data from a @@ -42,7 +42,7 @@ contacting the server, and does the actual authentication. C API ----- -The credential C API is meant to be called by git code which needs to +The credential C API is meant to be called by Git code which needs to acquire or store a credential. It is centered around an object representing a single credential and provides three basic operations: fill (acquire credentials by calling helpers and/or prompting the user), @@ -177,14 +177,14 @@ int foo_login(struct foo_connection *f) Credential Helpers ------------------ -Credential helpers are programs executed by git to fetch or save +Credential helpers are programs executed by Git to fetch or save credentials from and to long-term storage (where "long-term" is simply -longer than a single git process; e.g., credentials may be stored +longer than a single Git process; e.g., credentials may be stored in-memory for a few minutes, or indefinitely on disk). Each helper is specified by a single string in the configuration variable `credential.helper` (and others, see linkgit:git-config[1]). -The string is transformed by git into a command to be executed using +The string is transformed by Git into a command to be executed using these rules: 1. If the helper string begins with "!", it is considered a shell @@ -248,7 +248,7 @@ FORMAT` in linkgit:git-credential[7] for a detailed specification). For a `get` operation, the helper should produce a list of attributes on stdout in the same format. A helper is free to produce a subset, or even no values at all if it has nothing useful to provide. Any provided -attributes will overwrite those already known about by git. +attributes will overwrite those already known about by Git. For a `store` or `erase` operation, the helper's output is ignored. If it fails to perform the requested operation, it may complain to diff --git a/Documentation/technical/api-directory-listing.txt b/Documentation/technical/api-directory-listing.txt index add6f435b5..1f349b28ae 100644 --- a/Documentation/technical/api-directory-listing.txt +++ b/Documentation/technical/api-directory-listing.txt @@ -9,37 +9,40 @@ Data structure -------------- `struct dir_struct` structure is used to pass directory traversal -options to the library and to record the paths discovered. The notable -options are: +options to the library and to record the paths discovered. A single +`struct dir_struct` is used regardless of whether or not the traversal +recursively descends into subdirectories. + +The notable options are: `exclude_per_dir`:: The name of the file to be read in each directory for excluded files (typically `.gitignore`). -`collect_ignored`:: +`flags`:: - Include paths that are to be excluded in the result. + A bit-field of options: -`show_ignored`:: +`DIR_SHOW_IGNORED`::: The traversal is for finding just ignored files, not unignored files. -`show_other_directories`:: +`DIR_SHOW_OTHER_DIRECTORIES`::: Include a directory that is not tracked. -`hide_empty_directories`:: +`DIR_HIDE_EMPTY_DIRECTORIES`::: Do not include a directory that is not tracked and is empty. -`no_gitlinks`:: +`DIR_NO_GITLINKS`::: - If set, recurse into a directory that looks like a git + If set, recurse into a directory that looks like a Git directory. Otherwise it is shown as a directory. -The result of the enumeration is left in these fields:: +The result of the enumeration is left in these fields: `entries[]`:: @@ -64,11 +67,13 @@ marked. If you to exclude files, make sure you have loaded index first. * Prepare `struct dir_struct dir` and clear it with `memset(&dir, 0, sizeof(dir))`. -* Call `add_exclude()` to add single exclude pattern, - `add_excludes_from_file()` to add patterns from a file - (e.g. `.git/info/exclude`), and/or set `dir.exclude_per_dir`. A - short-hand function `setup_standard_excludes()` can be used to set up - the standard set of exclude settings. +* To add single exclude pattern, call `add_exclude_list()` and then + `add_exclude()`. + +* To add patterns from a file (e.g. `.git/info/exclude`), call + `add_excludes_from_file()` , and/or set `dir.exclude_per_dir`. A + short-hand function `setup_standard_excludes()` can be used to set + up the standard set of exclude settings. * Set options described in the Data Structure section above. @@ -76,4 +81,6 @@ marked. If you to exclude files, make sure you have loaded index first. * Use `dir.entries[]`. +* Call `clear_directory()` when none of the contained elements are no longer in use. + (JC) diff --git a/Documentation/technical/api-history-graph.txt b/Documentation/technical/api-history-graph.txt index d6fc90ac7e..18142b6d29 100644 --- a/Documentation/technical/api-history-graph.txt +++ b/Documentation/technical/api-history-graph.txt @@ -33,11 +33,11 @@ The following utility functions are wrappers around `graph_next_line()` and They can all be called with a NULL graph argument, in which case no graph output will be printed. -* `graph_show_commit()` calls `graph_next_line()` until it returns non-zero. - This prints all graph lines up to, and including, the line containing this - commit. Output is printed to stdout. The last line printed does not contain - a terminating newline. This should not be called if the commit line has - already been printed, or it will loop forever. +* `graph_show_commit()` calls `graph_next_line()` and + `graph_is_commit_finished()` until one of them return non-zero. This prints + all graph lines up to, and including, the line containing this commit. + Output is printed to stdout. The last line printed does not contain a + terminating newline. * `graph_show_oneline()` calls `graph_next_line()` and prints the result to stdout. The line printed does not contain a terminating newline. diff --git a/Documentation/technical/api-index-skel.txt b/Documentation/technical/api-index-skel.txt index af7cc2e395..eda8c195c1 100644 --- a/Documentation/technical/api-index-skel.txt +++ b/Documentation/technical/api-index-skel.txt @@ -1,7 +1,7 @@ -GIT API Documents +Git API Documents ================= -GIT has grown a set of internal API over time. This collection +Git has grown a set of internal API over time. This collection documents them. //////////////////////////////////////////////////////////////// @@ -11,5 +11,3 @@ documents them. //////////////////////////////////////////////////////////////// // table of contents end //////////////////////////////////////////////////////////////// - -2007-11-24 diff --git a/Documentation/technical/api-parse-options.txt b/Documentation/technical/api-parse-options.txt index 3062389404..32ddc1cf13 100644 --- a/Documentation/technical/api-parse-options.txt +++ b/Documentation/technical/api-parse-options.txt @@ -1,7 +1,7 @@ parse-options API ================= -The parse-options API is used to parse and massage options in git +The parse-options API is used to parse and massage options in Git and to provide a usage help with consistent look. Basics diff --git a/Documentation/technical/api-remote.txt b/Documentation/technical/api-remote.txt index c54b17db69..4be87768f6 100644 --- a/Documentation/technical/api-remote.txt +++ b/Documentation/technical/api-remote.txt @@ -3,7 +3,7 @@ Remotes configuration API The API in remote.h gives access to the configuration related to remotes. It handles all three configuration mechanisms historically -and currently used by git, and presents the information in a uniform +and currently used by Git, and presents the information in a uniform fashion. Note that the code also handles plain URLs without any configuration, giving them just the default information. @@ -45,7 +45,7 @@ struct remote `receivepack`, `uploadpack`:: The configured helper programs to run on the remote side, for - git-native protocols. + Git-native protocols. `http_proxy`:: diff --git a/Documentation/technical/api-run-command.txt b/Documentation/technical/api-run-command.txt index f18b4f4817..5d7d7f2d32 100644 --- a/Documentation/technical/api-run-command.txt +++ b/Documentation/technical/api-run-command.txt @@ -55,10 +55,8 @@ The functions above do the following: non-zero. . If the program terminated due to a signal, then the return value is the - signal number - 128, ie. it is negative and so indicates an unusual - condition; a diagnostic is printed. This return value can be passed to - exit(2), which will report the same code to the parent process that a - POSIX shell's $? would report for a program that died from the signal. + signal number + 128, ie. the same value that a POSIX shell's $? would + report. A diagnostic is printed. `start_async`:: diff --git a/Documentation/technical/api-strbuf.txt b/Documentation/technical/api-strbuf.txt index 84686b5c69..2c59cb2259 100644 --- a/Documentation/technical/api-strbuf.txt +++ b/Documentation/technical/api-strbuf.txt @@ -156,6 +156,11 @@ then they will free() it. Remove the bytes between `pos..pos+len` and replace it with the given data. +`strbuf_add_commented_lines`:: + + Add a NUL-terminated string to the buffer. Each line will be prepended + by a comment character and a blank. + `strbuf_add`:: Add data of given length to the buffer. @@ -229,6 +234,11 @@ which can be used by the programmer of the callback as she sees fit. Add a formatted string to the buffer. +`strbuf_commented_addf`:: + + Add a formatted string prepended by a comment character and a + blank to the buffer. + `strbuf_fread`:: Read a given size of data from a FILE* pointer to the buffer. diff --git a/Documentation/technical/api-string-list.txt b/Documentation/technical/api-string-list.txt index 7386bcab3e..20be348834 100644 --- a/Documentation/technical/api-string-list.txt +++ b/Documentation/technical/api-string-list.txt @@ -82,14 +82,6 @@ Functions call free() on the util members of any items that have to be deleted. Preserve the order of the items that are retained. -`string_list_longest_prefix`:: - - Return the longest string within a string_list that is a - prefix (in the sense of prefixcmp()) of the specified string, - or NULL if no such prefix exists. This function does not - require the string_list to be sorted (it does a linear - search). - `print_string_list`:: Dump a string_list to stdout, useful mainly for debugging purposes. It diff --git a/Documentation/technical/index-format.txt b/Documentation/technical/index-format.txt index 57d6f915b1..27c716b15f 100644 --- a/Documentation/technical/index-format.txt +++ b/Documentation/technical/index-format.txt @@ -1,7 +1,7 @@ -GIT index format +Git index format ================ -== The git index file has the following format +== The Git index file has the following format All binary numbers are in network byte order. Version 2 is described here unless stated otherwise. @@ -21,9 +21,9 @@ GIT index format - Extensions Extensions are identified by signature. Optional extensions can - be ignored if GIT does not understand them. + be ignored if Git does not understand them. - GIT currently supports cached tree and resolve undo extensions. + Git currently supports cached tree and resolve undo extensions. 4-byte extension signature. If the first byte is 'A'..'Z' the extension is optional and can be ignored. @@ -161,8 +161,9 @@ GIT index format this span of index as a tree. An entry can be in an invalidated state and is represented by having - -1 in the entry_count field. In this case, there is no object name - and the next entry starts immediately after the newline. + a negative number in the entry_count field. In this case, there is no + object name and the next entry starts immediately after the newline. + When writing an invalid entry, -1 should always be used as entry_count. The entries are written out in the top-down, depth-first order. The first entry represents the root level of the repository, followed by the diff --git a/Documentation/technical/pack-format.txt b/Documentation/technical/pack-format.txt index a7871fb865..0e37ec9de5 100644 --- a/Documentation/technical/pack-format.txt +++ b/Documentation/technical/pack-format.txt @@ -1,4 +1,4 @@ -GIT pack format +Git pack format =============== == pack-*.pack files have the following format: @@ -9,7 +9,7 @@ GIT pack format The signature is: {'P', 'A', 'C', 'K'} 4-byte version number (network byte order): - GIT currently accepts version number 2 or 3 but + Git currently accepts version number 2 or 3 but generates version 2 only. 4-byte number of objects contained in the pack (network byte order) diff --git a/Documentation/technical/pack-heuristics.txt b/Documentation/technical/pack-heuristics.txt index 103eb5d989..dbdf7ba9c8 100644 --- a/Documentation/technical/pack-heuristics.txt +++ b/Documentation/technical/pack-heuristics.txt @@ -5,11 +5,11 @@ Where do I go to learn the details - of git's packing heuristics? + of Git's packing heuristics? Be careful what you ask! -Followers of the git, please open the git IRC Log and turn to +Followers of the Git, please open the Git IRC Log and turn to February 10, 2006. It's a rare occasion, and we are joined by the King Git Himself, @@ -19,7 +19,7 @@ and seeks enlightenment. Others are present, but silent. Let's listen in! <njs`> Oh, here's a really stupid question -- where do I go to - learn the details of git's packing heuristics? google avails + learn the details of Git's packing heuristics? google avails me not, reading the source didn't help a lot, and wading through the whole mailing list seems less efficient than any of that. @@ -37,7 +37,7 @@ Ah! Modesty after all. <linus> njs, I don't think the docs exist. That's something where I don't think anybody else than me even really got involved. - Most of the rest of git others have been busy with (especially + Most of the rest of Git others have been busy with (especially Junio), but packing nobody touched after I did it. It's cryptic, yet vague. Linus in style for sure. Wise men @@ -57,7 +57,7 @@ Bait... And switch. That ought to do it! - <linus> Remember: git really doesn't follow files. So what it does is + <linus> Remember: Git really doesn't follow files. So what it does is - generate a list of all objects - sort the list according to magic heuristics - walk the list, using a sliding window, seeing if an object @@ -382,7 +382,7 @@ The 'net never forgets, so that should be good until the end of time. <njs`> (if only it happened more...) <linus> Anyway, the pack-file could easily be denser still, but - because it's used both for streaming (the git protocol) and + because it's used both for streaming (the Git protocol) and for on-disk, it has a few pessimizations. Actually, it is a made-up word. But it is a made-up word being @@ -432,12 +432,12 @@ Gasp! OK, saved. That's a fair Engineering trade off. Close call! In fact, Linus reflects on some Basic Engineering Fundamentals, design options, etc. - <linus> More importantly, they allow git to still _conceptually_ + <linus> More importantly, they allow Git to still _conceptually_ never deal with deltas at all, and be a "whole object" store. Which has some problems (we discussed bad huge-file - behaviour on the git lists the other day), but it does mean - that the basic git concepts are really really simple and + behaviour on the Git lists the other day), but it does mean + that the basic Git concepts are really really simple and straightforward. It's all been quite stable. @@ -461,6 +461,6 @@ Nuff said. <njs`> :-) <njs`> appreciate the infodump, I really was failing to find the - details on git packs :-) + details on Git packs :-) And now you know the rest of the story. diff --git a/Documentation/technical/racy-git.txt b/Documentation/technical/racy-git.txt index 53aa0c82c2..6dc82ca5a8 100644 --- a/Documentation/technical/racy-git.txt +++ b/Documentation/technical/racy-git.txt @@ -1,21 +1,21 @@ -Use of index and Racy git problem +Use of index and Racy Git problem ================================= Background ---------- -The index is one of the most important data structures in git. +The index is one of the most important data structures in Git. It represents a virtual working tree state by recording list of paths and their object names and serves as a staging area to write out the next tree object to be committed. The state is "virtual" in the sense that it does not necessarily have to, and often does not, match the files in the working tree. -There are cases git needs to examine the differences between the +There are cases Git needs to examine the differences between the virtual working tree state in the index and the files in the working tree. The most obvious case is when the user asks `git diff` (or its low level implementation, `git diff-files`) or -`git-ls-files --modified`. In addition, git internally checks +`git-ls-files --modified`. In addition, Git internally checks if the files in the working tree are different from what are recorded in the index to avoid stomping on local changes in them during patch application, switching branches, and merging. @@ -24,16 +24,16 @@ In order to speed up this comparison between the files in the working tree and the index entries, the index entries record the information obtained from the filesystem via `lstat(2)` system call when they were last updated. When checking if they differ, -git first runs `lstat(2)` on the files and compares the result +Git first runs `lstat(2)` on the files and compares the result with this information (this is what was originally done by the `ce_match_stat()` function, but the current code does it in `ce_match_stat_basic()` function). If some of these "cached -stat information" fields do not match, git can tell that the +stat information" fields do not match, Git can tell that the files are modified without even looking at their contents. Note: not all members in `struct stat` obtained via `lstat(2)` are used for this comparison. For example, `st_atime` obviously -is not useful. Currently, git compares the file type (regular +is not useful. Currently, Git compares the file type (regular files vs symbolic links) and executable bits (only for regular files) from `st_mode` member, `st_mtime` and `st_ctime` timestamps, `st_uid`, `st_gid`, `st_ino`, and `st_size` members. @@ -49,7 +49,7 @@ of git://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git ([PATCH] Sync in core time granuality with filesystems, 2005-01-04). -Racy git +Racy Git -------- There is one slight problem with the optimization based on the @@ -67,13 +67,13 @@ timestamp does not change, after this sequence, the cached stat information the index entry records still exactly match what you would see in the filesystem, even though the file `foo` is now different. -This way, git can incorrectly think files in the working tree +This way, Git can incorrectly think files in the working tree are unmodified even though they actually are. This is called -the "racy git" problem (discovered by Pasky), and the entries +the "racy Git" problem (discovered by Pasky), and the entries that appear clean when they may not be because of this problem are called "racily clean". -To avoid this problem, git does two things: +To avoid this problem, Git does two things: . When the cached stat information says the file has not been modified, and the `st_mtime` is the same as (or newer than) @@ -116,7 +116,7 @@ timestamp comparison check done with the former logic anymore. The latter makes sure that the cached stat information for `foo` would never match with the file in the working tree, so later checks by `ce_match_stat_basic()` would report that the index entry -does not match the file and git does not have to fall back on more +does not match the file and Git does not have to fall back on more expensive `ce_modified_check_fs()`. @@ -159,7 +159,7 @@ of the cached stat information. Avoiding runtime penalty ------------------------ -In order to avoid the above runtime penalty, post 1.4.2 git used +In order to avoid the above runtime penalty, post 1.4.2 Git used to have a code that made sure the index file got timestamp newer than the youngest files in the index when there are many young files with the same timestamp as the diff --git a/Documentation/technical/shallow.txt b/Documentation/technical/shallow.txt index 0502a5471e..ea2f69faf5 100644 --- a/Documentation/technical/shallow.txt +++ b/Documentation/technical/shallow.txt @@ -53,3 +53,6 @@ It also writes an appropriate $GIT_DIR/shallow. You can deepen a shallow repository with "git-fetch --depth 20 repo branch", which will fetch branch from repo, but stop at depth 20, updating $GIT_DIR/shallow. + +The special depth 2147483647 (or 0x7fffffff, the largest positive +number a signed 32-bit integer can contain) means infinite depth. |