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Merge pull request #1874 from mikeando/doc_cleanup2

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Fixed formatting of diff-internals.md
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Vicent Martí 2013-09-25 01:40:43 -07:00
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@ -45,44 +45,48 @@ Internal Objects
* `git_diff_file_content` is an internal structure that represents the * `git_diff_file_content` is an internal structure that represents the
data on one side of an item to be diffed; it is an augmented data on one side of an item to be diffed; it is an augmented
`git_diff_file` with more flags and the actual file data. `git_diff_file` with more flags and the actual file data.
** it is created from a repository plus a) a git_diff_file, b) a git_blob,
* it is created from a repository plus a) a git_diff_file, b) a git_blob,
or c) raw data and size or c) raw data and size
** there are three main operations on git_diff_file_content: * there are three main operations on git_diff_file_content:
*** _initialization_ sets up the data structure and does what it can up to,
but not including loading and looking at the actual data * _initialization_ sets up the data structure and does what it can up to,
*** _loading_ loads the data, preprocesses it (i.e. applies filters) and but not including loading and looking at the actual data
potentially analyzes it (to decide if binary) * _loading_ loads the data, preprocesses it (i.e. applies filters) and
*** _free_ releases loaded data and frees any allocated memory potentially analyzes it (to decide if binary)
* _free_ releases loaded data and frees any allocated memory
* The internal structure of a `git_diff_patch` stores the actual diff * The internal structure of a `git_diff_patch` stores the actual diff
between a pair of `git_diff_file_content` items between a pair of `git_diff_file_content` items
** it may be "unset" if the items are not diffable
** "empty" if the items are the same * it may be "unset" if the items are not diffable
** otherwise it will consist of a set of hunks each of which covers some * "empty" if the items are the same
number of lines of context, additions and deletions * otherwise it will consist of a set of hunks each of which covers some
** a patch is created from two git_diff_file_content items number of lines of context, additions and deletions
** a patch is fully instantiated in three phases: * a patch is created from two git_diff_file_content items
*** initial creation and initialization * a patch is fully instantiated in three phases:
*** loading of data and preliminary data examination
*** diffing of data and optional storage of diffs * initial creation and initialization
** (TBD) if a patch is asked to store the diffs and the size of the diff * loading of data and preliminary data examination
is significantly smaller than the raw data of the two sides, then the * diffing of data and optional storage of diffs
patch may be flattened using a pool of string data * (TBD) if a patch is asked to store the diffs and the size of the diff
is significantly smaller than the raw data of the two sides, then the
patch may be flattened using a pool of string data
* `git_diff_output` is an internal structure that represents an output * `git_diff_output` is an internal structure that represents an output
target for a `git_diff_patch` target for a `git_diff_patch`
** It consists of file, hunk, and line callbacks, plus a payload * It consists of file, hunk, and line callbacks, plus a payload
** There is a standard flattened output that can be used for plain text output * There is a standard flattened output that can be used for plain text output
** Typically we use a `git_xdiff_output` which drives the callbacks via the * Typically we use a `git_xdiff_output` which drives the callbacks via the
xdiff code taken from core Git. xdiff code taken from core Git.
* `git_diff_driver` is an internal structure that encapsulates the logic * `git_diff_driver` is an internal structure that encapsulates the logic
for a given type of file for a given type of file
** a driver is looked up based on the name and mode of a file. * a driver is looked up based on the name and mode of a file.
** the driver can then be used to: * the driver can then be used to:
*** determine if a file is binary (by attributes, by git_diff_options * determine if a file is binary (by attributes, by git_diff_options
settings, or by examining the content) settings, or by examining the content)
*** give you a function pointer that is used to evaluate function context * give you a function pointer that is used to evaluate function context
for hunk headers for hunk headers
** At some point, the logic for getting a filtered version of file content * At some point, the logic for getting a filtered version of file content
or calculating the OID of a file may be moved into the driver. or calculating the OID of a file may be moved into the driver.