diff options
Diffstat (limited to 'Documentation/technical')
21 files changed, 184 insertions, 110 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-argv-array.txt b/Documentation/technical/api-argv-array.txt index 1a797812fb..a6b7d83a8e 100644 --- a/Documentation/technical/api-argv-array.txt +++ b/Documentation/technical/api-argv-array.txt @@ -53,3 +53,11 @@ Functions `argv_array_clear`:: Free all memory associated with the array and return it to the initial, empty state. + +`argv_array_detach`:: + Detach the argv array from the `struct argv_array`, transferring + ownership of the allocated array and strings. + +`argv_array_free_detached`:: + Free the memory allocated by a `struct argv_array` that was later + detached and is now no longer needed. 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-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..c1b42a40d3 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), @@ -160,7 +160,7 @@ int foo_login(struct foo_connection *f) break; default: /* - * Some other error occured. We don't know if the + * Some other error occurred. We don't know if the * credential is good or bad, so report nothing to the * credential subsystem. */ @@ -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..7f8e78d916 100644 --- a/Documentation/technical/api-directory-listing.txt +++ b/Documentation/technical/api-directory-listing.txt @@ -9,37 +9,51 @@ 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`:: + + A bit-field of options (the `*IGNORED*` flags are mutually exclusive): + +`DIR_SHOW_IGNORED`::: + + Return just ignored files in `entries[]`, not untracked files. + +`DIR_SHOW_IGNORED_TOO`::: - Include paths that are to be excluded in the result. + Similar to `DIR_SHOW_IGNORED`, but return ignored files in `ignored[]` + in addition to untracked files in `entries[]`. -`show_ignored`:: +`DIR_COLLECT_IGNORED`::: - The traversal is for finding just ignored files, not unignored - files. + Special mode for git-add. Return ignored files in `ignored[]` and + untracked files in `entries[]`. Only returns ignored files that match + pathspec exactly (no wildcards). Does not recurse into ignored + directories. -`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[]`:: @@ -54,6 +68,14 @@ The result of the enumeration is left in these fields:: Internal use; keeps track of allocation of `entries[]` array. +`ignored[]`:: + + An array of `struct dir_entry`, used for ignored paths with the + `DIR_SHOW_IGNORED_TOO` and `DIR_COLLECT_IGNORED` flags. + +`ignored_nr`:: + + The number of members in `ignored[]` array. Calling sequence ---------------- @@ -64,11 +86,13 @@ 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 +100,6 @@ 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 730cfacf78..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. //////////////////////////////////////////////////////////////// diff --git a/Documentation/technical/api-parse-options.txt b/Documentation/technical/api-parse-options.txt index 3062389404..1317db4d6c 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 @@ -41,6 +41,8 @@ The parse-options API allows: * Boolean long options can be 'negated' (or 'unset') by prepending `no-`, e.g. `--no-abbrev` instead of `--abbrev`. Conversely, options that begin with `no-` can be 'negated' by removing it. + Other long options can be unset (e.g., set string to NULL, set + integer to 0) by prepending `no-`. * Options and non-option arguments can clearly be separated using the `--` option, e.g. `-a -b --option -- --this-is-a-file` indicates that @@ -174,6 +176,10 @@ There are some macros to easily define options: Introduce an option with date argument, see `approxidate()`. The timestamp is put into `int_var`. +`OPT_EXPIRY_DATE(short, long, &int_var, description)`:: + Introduce an option with expiry date argument, see `parse_expiry_date()`. + The timestamp is put into `int_var`. + `OPT_CALLBACK(short, long, &var, arg_str, description, func_ptr)`:: Introduce an option with argument. The argument will be fed into the function given by `func_ptr` diff --git a/Documentation/technical/api-ref-iteration.txt b/Documentation/technical/api-ref-iteration.txt index dbbea95db7..aa1c50f181 100644 --- a/Documentation/technical/api-ref-iteration.txt +++ b/Documentation/technical/api-ref-iteration.txt @@ -35,7 +35,7 @@ Iteration functions * `head_ref_submodule()`, `for_each_ref_submodule()`, `for_each_ref_in_submodule()`, `for_each_tag_ref_submodule()`, `for_each_branch_ref_submodule()`, `for_each_remote_ref_submodule()` - do the same as the functions descibed above but for a specified + do the same as the functions described above but for a specified submodule. * `for_each_rawref()` can be used to learn about broken ref and symref. 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-sha1-array.txt b/Documentation/technical/api-sha1-array.txt index 45d1c517cd..3e75497a37 100644 --- a/Documentation/technical/api-sha1-array.txt +++ b/Documentation/technical/api-sha1-array.txt @@ -1,7 +1,7 @@ sha1-array API ============== -The sha1-array API provides storage and manipulation of sets of SHA1 +The sha1-array API provides storage and manipulation of sets of SHA-1 identifiers. The emphasis is on storage and processing efficiency, making them suitable for large lists. Note that the ordering of items is not preserved over some operations. @@ -11,7 +11,7 @@ Data Structures `struct sha1_array`:: - A single array of SHA1 hashes. This should be initialized by + A single array of SHA-1 hashes. This should be initialized by assignment from `SHA1_ARRAY_INIT`. The `sha1` member contains the actual data. The `nr` member contains the number of items in the set. The `alloc` and `sorted` members are used internally, diff --git a/Documentation/technical/api-strbuf.txt b/Documentation/technical/api-strbuf.txt index 95a8bf3846..3350d97dda 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. @@ -225,10 +230,20 @@ which can be used by the programmer of the callback as she sees fit. destination. This is useful for literal data to be fed to either strbuf_expand or to the *printf family of functions. +`strbuf_humanise_bytes`:: + + Append the given byte size as a human-readable string (i.e. 12.23 KiB, + 3.50 MiB). + `strbuf_addf`:: 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. @@ -279,6 +294,22 @@ same behaviour as well. Strip whitespace from a buffer. The second parameter controls if comments are considered contents to be removed or not. +`strbuf_split_buf`:: +`strbuf_split_str`:: +`strbuf_split_max`:: +`strbuf_split`:: + + Split a string or strbuf into a list of strbufs at a specified + terminator character. The returned substrings include the + terminator characters. Some of these functions take a `max` + parameter, which, if positive, limits the output to that + number of substrings. + +`strbuf_list_free`:: + + Free a list of strbufs (for example, the return values of the + `strbuf_split()` functions). + `launch_editor`:: Launch the user preferred editor to edit a file and fill the buffer diff --git a/Documentation/technical/api-string-list.txt b/Documentation/technical/api-string-list.txt index 94d7a2bd99..20be348834 100644 --- a/Documentation/technical/api-string-list.txt +++ b/Documentation/technical/api-string-list.txt @@ -38,7 +38,8 @@ member (you need this if you add things later) and you should set the `unsorted_string_list_delete_item`. . Can remove items not matching a criterion from a sorted or unsorted - list using `filter_string_list`. + list using `filter_string_list`, or remove empty strings using + `string_list_remove_empty_items`. . Finally it should free the list using `string_list_clear`. @@ -75,13 +76,11 @@ Functions to be deleted. Preserve the order of the items that are retained. -`string_list_longest_prefix`:: +`string_list_remove_empty_items`:: - 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). + Remove any empty strings from the list. If free_util is true, + call free() on the util members of any items that have to be + deleted. Preserve the order of the items that are retained. `print_string_list`:: diff --git a/Documentation/technical/index-format.txt b/Documentation/technical/index-format.txt index 7324154838..0810251f5a 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. @@ -12,7 +12,7 @@ GIT index format The signature is { 'D', 'I', 'R', 'C' } (stands for "dircache") 4-byte version number: - The current supported versions are 2 and 3. + The current supported versions are 2, 3 and 4. 32-bit number of index entries. @@ -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. @@ -93,8 +93,8 @@ GIT index format 12-bit name length if the length is less than 0xFFF; otherwise 0xFFF is stored in this field. - (Version 3) A 16-bit field, only applicable if the "extended flag" - above is 1, split into (high to low bits). + (Version 3 or later) A 16-bit field, only applicable if the + "extended flag" above is 1, split into (high to low bits). 1-bit reserved for future diff --git a/Documentation/technical/pack-format.txt b/Documentation/technical/pack-format.txt index a7871fb865..8e5bf60be3 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) @@ -26,13 +26,15 @@ GIT pack format (deltified representation) n-byte type and length (3-bit type, (n-1)*7+4-bit length) - 20-byte base object name + 20-byte base object name if OBJ_REF_DELTA or a negative relative + offset from the delta object's position in the pack if this + is an OBJ_OFS_DELTA object compressed delta data Observation: length of each object is encoded in a variable length format and is not constrained to 32-bit or anything. - - The trailer records 20-byte SHA1 checksum of all of the above. + - The trailer records 20-byte SHA-1 checksum of all of the above. == Original (version 1) pack-*.idx files have the following format: @@ -53,10 +55,10 @@ GIT pack format - The file is concluded with a trailer: - A copy of the 20-byte SHA1 checksum at the end of + A copy of the 20-byte SHA-1 checksum at the end of corresponding packfile. - 20-byte SHA1-checksum of all of the above. + 20-byte SHA-1-checksum of all of the above. Pack Idx file: @@ -104,7 +106,7 @@ Pack file entry: <+ If it is not DELTA, then deflated bytes (the size above is the size before compression). If it is REF_DELTA, then - 20-byte base object name SHA1 (the size above is the + 20-byte base object name SHA-1 (the size above is the size of the delta data that follows). delta data, deflated. If it is OFS_DELTA, then @@ -133,7 +135,7 @@ Pack file entry: <+ - A 256-entry fan-out table just like v1. - - A table of sorted 20-byte SHA1 object names. These are + - A table of sorted 20-byte SHA-1 object names. These are packed together without offset values to reduce the cache footprint of the binary search for a specific object name. @@ -154,7 +156,7 @@ Pack file entry: <+ - The same trailer as a v1 pack file: - A copy of the 20-byte SHA1 checksum at the end of + A copy of the 20-byte SHA-1 checksum at the end of corresponding packfile. - 20-byte SHA1-checksum of all of the above. + 20-byte SHA-1-checksum of all of the above. diff --git a/Documentation/technical/pack-heuristics.txt b/Documentation/technical/pack-heuristics.txt index 103eb5d989..8b7ae1c140 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 @@ -89,7 +89,7 @@ Ah, grasshopper! And thus the enlightenment begins anew. <linus> The "magic" is actually in theory totally arbitrary. ANY order will give you a working pack, but no, it's not - ordered by SHA1. + ordered by SHA-1. Before talking about the ordering for the sliding delta window, let's talk about the recency order. That's more @@ -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/pack-protocol.txt b/Documentation/technical/pack-protocol.txt index f1a51edf47..b898e97988 100644 --- a/Documentation/technical/pack-protocol.txt +++ b/Documentation/technical/pack-protocol.txt @@ -228,8 +228,7 @@ obtained through ref discovery. The client MUST write all obj-ids which it only has shallow copies of (meaning that it does not have the parents of a commit) as 'shallow' lines so that the server is aware of the limitations of -the client's history. Clients MUST NOT mention an obj-id which -it does not know exists on the server. +the client's history. The client now sends the maximum commit history depth it wants for this transaction, which is the number of commits it wants from the 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..5183b15422 100644 --- a/Documentation/technical/shallow.txt +++ b/Documentation/technical/shallow.txt @@ -8,7 +8,7 @@ repo, and therefore grafts are introduced pretending that these commits have no parents. ********************************************************* -The basic idea is to write the SHA1s of shallow commits into +The basic idea is to write the SHA-1s of shallow commits into $GIT_DIR/shallow, and handle its contents like the contents of $GIT_DIR/info/grafts (with the difference that shallow cannot contain parent information). @@ -18,7 +18,7 @@ even the config, since the user should not touch that file at all (even throughout development of the shallow clone, it was never manually edited!). -Each line contains exactly one SHA1. When read, a commit_graft +Each line contains exactly one SHA-1. When read, a commit_graft will be constructed, which has nr_parent < 0 to make it easier to discern from user provided grafts. @@ -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. |