Add history graph API
This new API allows the commit history to be displayed as a text-based graphical representation. Signed-off-by: Adam Simpkins <adam@adamsimpkins.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Adam Simpkins
Junio C Hamano
parent
885cf80899
commit
c12172d2ea
176
Documentation/technical/api-history-graph.txt
Normal file
176
Documentation/technical/api-history-graph.txt
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@ -0,0 +1,176 @@
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history graph API
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=================
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The graph API is used to draw a text-based representation of the commit
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history. The API generates the graph in a line-by-line fashion.
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Functions
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---------
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Core functions:
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* `graph_init()` creates a new `struct git_graph`
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* `graph_release()` destroys a `struct git_graph`, and frees the memory
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associated with it.
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* `graph_update()` moves the graph to a new commit.
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* `graph_next_line()` outputs the next line of the graph into a strbuf. It
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does not add a terminating newline.
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* `graph_padding_line()` outputs a line of vertical padding in the graph. It
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is similar to `graph_next_line()`, but is guaranteed to never print the line
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containing the current commit. Where `graph_next_line()` would print the
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commit line next, `graph_padding_line()` prints a line that simply extends
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all branch lines downwards one row, leaving their positions unchanged.
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* `graph_is_commit_finished()` determines if the graph has output all lines
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necessary for the current commit. If `graph_update()` is called before all
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lines for the current commit have been printed, the next call to
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`graph_next_line()` will output an ellipsis, to indicate that a portion of
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the graph was omitted.
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The following utility functions are wrappers around `graph_next_line()` and
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`graph_is_commit_finished()`. They always print the output to stdout.
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They can all be called with a NULL graph argument, in which case no graph
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output will be printed.
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* `graph_show_commit()` calls `graph_next_line()` until it returns non-zero.
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This prints all graph lines up to, and including, the line containing this
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commit. Output is printed to stdout. The last line printed does not contain
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a terminating newline. This should not be called if the commit line has
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already been printed, or it will loop forever.
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* `graph_show_oneline()` calls `graph_next_line()` and prints the result to
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stdout. The line printed does not contain a terminating newline.
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* `graph_show_padding()` calls `graph_padding_line()` and prints the result to
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stdout. The line printed does not contain a terminating newline.
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* `graph_show_remainder()` calls `graph_next_line()` until
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`graph_is_commit_finished()` returns non-zero. Output is printed to stdout.
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The last line printed does not contain a terminating newline. Returns 1 if
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output was printed, and 0 if no output was necessary.
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* `graph_show_strbuf()` prints the specified strbuf to stdout, prefixing all
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lines but the first with a graph line. The caller is responsible for
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ensuring graph output for the first line has already been printed to stdout.
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(This can be done with `graph_show_commit()` or `graph_show_oneline()`.) If
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a NULL graph is supplied, the strbuf is printed as-is.
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* `graph_show_commit_msg()` is similar to `graph_show_strbuf()`, but it also
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prints the remainder of the graph, if more lines are needed after the strbuf
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ends. It is better than directly calling `graph_show_strbuf()` followed by
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`graph_show_remainder()` since it properly handles buffers that do not end in
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a terminating newline. The output printed by `graph_show_commit_msg()` will
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end in a newline if and only if the strbuf ends in a newline.
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Data structure
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--------------
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`struct git_graph` is an opaque data type used to store the current graph
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state.
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Calling sequence
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----------------
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* Create a `struct git_graph` by calling `graph_init()`.
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* Use the revision walking API to walk through a group of contiguous commits.
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* For each commit traversed, call `graph_update()` to move the graph to the
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next commit. Once `graph_update()` has been called, call `graph_next_line()`
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repeatedly, until `graph_is_commit_finished()` returns non-zero. Each call
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to `graph_next_line()` will output a single line of the graph. The resulting
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lines will not contain any newlines. `graph_next_line()` returns 1 if the
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resulting line contains the current commit, or 0 if this is merely a line
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needed to adjust the graph before or after the current commit. This return
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value can be used to determine where to print the commit summary information
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alongside the graph output.
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Limitations
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-----------
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* `graph_update()` must be called with commits in topological order. It should
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not be called on a commit if it has already been invoked with an ancestor of
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that commit, or the graph output will be incorrect.
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* `graph_update()` must be called on a contiguous group of commits. If
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`graph_update()` is called on a particular commit, it should later be called
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on all parents of that commit. Parents must not be skipped, or the graph
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output will appear incorrect.
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+
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`graph_update()` may be used on a pruned set of commits only if the parent list
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has been rewritten so as to include only ancestors from the pruned set.
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* The graph API does not currently support reverse commit ordering. In
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order to implement reverse ordering, the graphing API needs an
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(efficient) mechanism to find the children of a commit.
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Sample usage
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------------
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------------
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struct commit *commit;
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struct git_graph *graph = graph_init();
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while ((commit = get_revision(opts)) != NULL) {
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graph_update(graph, commit);
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while (!graph_is_commit_finished(graph))
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{
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struct strbuf sb;
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int is_commit_line;
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strbuf_init(&sb, 0);
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is_commit_line = graph_next_line(graph, &sb);
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fputs(sb.buf, stdout);
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if (is_commit_line)
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log_tree_commit(opts, commit);
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else
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putchar(opts->diffopt.line_termination);
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}
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}
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graph_release(graph);
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------------
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Sample output
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-------------
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The following is an example of the output from the graph API. This output does
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not include any commit summary information--callers are responsible for
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outputting that information, if desired.
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------------
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*
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*
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M
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* |
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| | *
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| \ \
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| \ \
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M-. \ \
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|\ \ \ \
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| | * | |
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| | | | | *
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| | | | | *
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| | | | | M
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| | | | | |\
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| | | | | | *
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| * | | | | |
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| | | | | M \
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| | | | | |\ |
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| | | | * | | |
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| | | | * | | |
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* | | | | | | |
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| |/ / / / / /
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|/| / / / / /
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* | | | | | |
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|/ / / / / /
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* | | | | |
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| | | | | *
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| | | | |/
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| | | | *
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------------
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2
Makefile
2
Makefile
@ -346,6 +346,7 @@ LIB_H += diff.h
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LIB_H += dir.h
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LIB_H += fsck.h
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LIB_H += git-compat-util.h
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LIB_H += graph.h
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LIB_H += grep.h
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LIB_H += hash.h
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LIB_H += list-objects.h
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@ -411,6 +412,7 @@ LIB_OBJS += entry.o
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LIB_OBJS += environment.o
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LIB_OBJS += exec_cmd.o
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LIB_OBJS += fsck.o
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LIB_OBJS += graph.o
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LIB_OBJS += grep.o
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LIB_OBJS += hash.o
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LIB_OBJS += help.o
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907
graph.c
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907
graph.c
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@ -0,0 +1,907 @@
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#include "cache.h"
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#include "commit.h"
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#include "graph.h"
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#include "diff.h"
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#include "revision.h"
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/*
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* TODO:
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* - Add colors to the graph.
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* Pick a color for each column, and print all characters
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* in that column with the specified color.
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*
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* - Limit the number of columns, similar to the way gitk does.
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* If we reach more than a specified number of columns, omit
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* sections of some columns.
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*
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* - The output during the GRAPH_PRE_COMMIT and GRAPH_COLLAPSING states
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* could be made more compact by printing horizontal lines, instead of
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* long diagonal lines. For example, during collapsing, something like
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* this: instead of this:
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* | | | | | | | | | |
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* | |_|_|/ | | | |/
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* |/| | | | | |/|
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* | | | | | |/| |
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* |/| | |
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* | | | |
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*
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* If there are several parallel diagonal lines, they will need to be
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* replaced with horizontal lines on subsequent rows.
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*/
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struct column {
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/*
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* The parent commit of this column.
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*/
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struct commit *commit;
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/*
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* XXX: Once we add support for colors, struct column could also
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* contain the color of its branch line.
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*/
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};
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enum graph_state {
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GRAPH_PADDING,
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GRAPH_SKIP,
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GRAPH_PRE_COMMIT,
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GRAPH_COMMIT,
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GRAPH_POST_MERGE,
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GRAPH_COLLAPSING
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};
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struct git_graph {
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/*
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* The commit currently being processed
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*/
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struct commit *commit;
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/*
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* The number of parents this commit has.
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* (Stored so we don't have to walk over them each time we need
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* this number)
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*/
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int num_parents;
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/*
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* The next expansion row to print
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* when state is GRAPH_PRE_COMMIT
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*/
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int expansion_row;
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/*
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* The current output state.
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* This tells us what kind of line graph_next_line() should output.
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*/
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enum graph_state state;
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/*
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* The maximum number of columns that can be stored in the columns
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* and new_columns arrays. This is also half the number of entries
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* that can be stored in the mapping and new_mapping arrays.
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*/
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int column_capacity;
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/*
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* The number of columns (also called "branch lines" in some places)
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*/
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int num_columns;
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/*
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* The number of columns in the new_columns array
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*/
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int num_new_columns;
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/*
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* The number of entries in the mapping array
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*/
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int mapping_size;
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/*
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* The column state before we output the current commit.
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*/
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struct column *columns;
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/*
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* The new column state after we output the current commit.
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* Only valid when state is GRAPH_COLLAPSING.
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*/
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struct column *new_columns;
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/*
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* An array that tracks the current state of each
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* character in the output line during state GRAPH_COLLAPSING.
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* Each entry is -1 if this character is empty, or a non-negative
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* integer if the character contains a branch line. The value of
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* the integer indicates the target position for this branch line.
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* (I.e., this array maps the current column positions to their
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* desired positions.)
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*
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* The maximum capacity of this array is always
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* sizeof(int) * 2 * column_capacity.
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*/
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int *mapping;
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/*
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* A temporary array for computing the next mapping state
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* while we are outputting a mapping line. This is stored as part
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* of the git_graph simply so we don't have to allocate a new
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* temporary array each time we have to output a collapsing line.
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*/
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int *new_mapping;
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};
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struct git_graph *graph_init(void)
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{
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struct git_graph *graph = xmalloc(sizeof(struct git_graph));
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graph->commit = NULL;
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graph->num_parents = 0;
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graph->expansion_row = 0;
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graph->state = GRAPH_PADDING;
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graph->num_columns = 0;
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graph->num_new_columns = 0;
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graph->mapping_size = 0;
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/*
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* Allocate a reasonably large default number of columns
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* We'll automatically grow columns later if we need more room.
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*/
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graph->column_capacity = 30;
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graph->columns = xmalloc(sizeof(struct column) *
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graph->column_capacity);
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graph->new_columns = xmalloc(sizeof(struct column) *
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graph->column_capacity);
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graph->mapping = xmalloc(sizeof(int) * 2 * graph->column_capacity);
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graph->new_mapping = xmalloc(sizeof(int) * 2 * graph->column_capacity);
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return graph;
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}
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void graph_release(struct git_graph *graph)
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{
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free(graph->columns);
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free(graph->new_columns);
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free(graph->mapping);
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free(graph);
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}
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static void graph_ensure_capacity(struct git_graph *graph, int num_columns)
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{
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if (graph->column_capacity >= num_columns)
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return;
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do {
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graph->column_capacity *= 2;
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} while (graph->column_capacity < num_columns);
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graph->columns = xrealloc(graph->columns,
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sizeof(struct column) *
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graph->column_capacity);
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graph->new_columns = xrealloc(graph->new_columns,
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sizeof(struct column) *
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graph->column_capacity);
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graph->mapping = xrealloc(graph->mapping,
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sizeof(int) * 2 * graph->column_capacity);
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graph->new_mapping = xrealloc(graph->new_mapping,
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sizeof(int) * 2 * graph->column_capacity);
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}
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static void graph_insert_into_new_columns(struct git_graph *graph,
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struct commit *commit,
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int *mapping_index)
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{
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int i;
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/*
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* Ignore uinteresting and pruned commits
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*/
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if (commit->object.flags & (UNINTERESTING | TREESAME))
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return;
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/*
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* If the commit is already in the new_columns list, we don't need to
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* add it. Just update the mapping correctly.
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*/
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for (i = 0; i < graph->num_new_columns; i++) {
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if (graph->new_columns[i].commit == commit) {
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graph->mapping[*mapping_index] = i;
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*mapping_index += 2;
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return;
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}
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}
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/*
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* This commit isn't already in new_columns. Add it.
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*/
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graph->new_columns[graph->num_new_columns].commit = commit;
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graph->mapping[*mapping_index] = graph->num_new_columns;
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*mapping_index += 2;
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graph->num_new_columns++;
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}
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static void graph_update_columns(struct git_graph *graph)
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{
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struct commit_list *parent;
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struct column *tmp_columns;
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int max_new_columns;
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int mapping_idx;
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int i, seen_this;
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/*
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* Swap graph->columns with graph->new_columns
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* graph->columns contains the state for the previous commit,
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* and new_columns now contains the state for our commit.
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*
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* We'll re-use the old columns array as storage to compute the new
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* columns list for the commit after this one.
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*/
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tmp_columns = graph->columns;
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graph->columns = graph->new_columns;
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graph->num_columns = graph->num_new_columns;
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graph->new_columns = tmp_columns;
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graph->num_new_columns = 0;
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/*
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* Now update new_columns and mapping with the information for the
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* commit after this one.
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*
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* First, make sure we have enough room. At most, there will
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* be graph->num_columns + graph->num_parents columns for the next
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* commit.
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*/
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max_new_columns = graph->num_columns + graph->num_parents;
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graph_ensure_capacity(graph, max_new_columns);
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/*
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* Clear out graph->mapping
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*/
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graph->mapping_size = 2 * max_new_columns;
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for (i = 0; i < graph->mapping_size; i++)
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graph->mapping[i] = -1;
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/*
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* Populate graph->new_columns and graph->mapping
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*
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* Some of the parents of this commit may already be in
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* graph->columns. If so, graph->new_columns should only contain a
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* single entry for each such commit. graph->mapping should
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* contain information about where each current branch line is
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* supposed to end up after the collapsing is performed.
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*/
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seen_this = 0;
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mapping_idx = 0;
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for (i = 0; i <= graph->num_columns; i++) {
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struct commit *col_commit;
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if (i == graph->num_columns) {
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if (seen_this)
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break;
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col_commit = graph->commit;
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} else {
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col_commit = graph->columns[i].commit;
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}
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if (col_commit == graph->commit) {
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seen_this = 1;
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for (parent = graph->commit->parents;
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parent;
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parent = parent->next) {
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graph_insert_into_new_columns(graph,
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parent->item,
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&mapping_idx);
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}
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} else {
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graph_insert_into_new_columns(graph, col_commit,
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&mapping_idx);
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}
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}
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/*
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* Shrink mapping_size to be the minimum necessary
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*/
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while (graph->mapping_size > 1 &&
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graph->mapping[graph->mapping_size - 1] < 0)
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graph->mapping_size--;
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}
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void graph_update(struct git_graph *graph, struct commit *commit)
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{
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struct commit_list *parent;
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/*
|
||||
* Set the new commit
|
||||
*/
|
||||
graph->commit = commit;
|
||||
|
||||
/*
|
||||
* Count how many parents this commit has
|
||||
*/
|
||||
graph->num_parents = 0;
|
||||
for (parent = commit->parents; parent; parent = parent->next)
|
||||
graph->num_parents++;
|
||||
|
||||
/*
|
||||
* Call graph_update_columns() to update
|
||||
* columns, new_columns, and mapping.
|
||||
*/
|
||||
graph_update_columns(graph);
|
||||
|
||||
graph->expansion_row = 0;
|
||||
|
||||
/*
|
||||
* Update graph->state.
|
||||
*
|
||||
* If the previous commit didn't get to the GRAPH_PADDING state,
|
||||
* it never finished its output. Goto GRAPH_SKIP, to print out
|
||||
* a line to indicate that portion of the graph is missing.
|
||||
*
|
||||
* Otherwise, if there are 3 or more parents, we need to print
|
||||
* extra rows before the commit, to expand the branch lines around
|
||||
* it and make room for it.
|
||||
*
|
||||
* If there are less than 3 parents, we can immediately print the
|
||||
* commit line.
|
||||
*/
|
||||
if (graph->state != GRAPH_PADDING)
|
||||
graph->state = GRAPH_SKIP;
|
||||
else if (graph->num_parents >= 3)
|
||||
graph->state = GRAPH_PRE_COMMIT;
|
||||
else
|
||||
graph->state = GRAPH_COMMIT;
|
||||
}
|
||||
|
||||
static int graph_is_mapping_correct(struct git_graph *graph)
|
||||
{
|
||||
int i;
|
||||
|
||||
/*
|
||||
* The mapping is up to date if each entry is at its target,
|
||||
* or is 1 greater than its target.
|
||||
* (If it is 1 greater than the target, '/' will be printed, so it
|
||||
* will look correct on the next row.)
|
||||
*/
|
||||
for (i = 0; i < graph->mapping_size; i++) {
|
||||
int target = graph->mapping[i];
|
||||
if (target < 0)
|
||||
continue;
|
||||
if (target == (i / 2))
|
||||
continue;
|
||||
return 0;
|
||||
}
|
||||
|
||||
return 1;
|
||||
}
|
||||
|
||||
static void graph_pad_horizontally(struct git_graph *graph, struct strbuf *sb)
|
||||
{
|
||||
/*
|
||||
* Add additional spaces to the end of the strbuf, so that all
|
||||
* lines for a particular commit have the same width.
|
||||
*
|
||||
* This way, fields printed to the right of the graph will remain
|
||||
* aligned for the entire commit.
|
||||
*
|
||||
* This computation results in 3 extra space to the right in most
|
||||
* cases, but only 1 extra space if the commit doesn't have any
|
||||
* children that have already been displayed in the graph (i.e.,
|
||||
* if the current commit isn't in graph->columns).
|
||||
*/
|
||||
size_t extra;
|
||||
size_t final_width = graph->num_columns + graph->num_parents;
|
||||
if (graph->num_parents < 1)
|
||||
final_width++;
|
||||
final_width *= 2;
|
||||
|
||||
if (sb->len >= final_width)
|
||||
return;
|
||||
|
||||
extra = final_width - sb->len;
|
||||
strbuf_addf(sb, "%*s", (int) extra, "");
|
||||
}
|
||||
|
||||
static void graph_output_padding_line(struct git_graph *graph,
|
||||
struct strbuf *sb)
|
||||
{
|
||||
int i;
|
||||
|
||||
/*
|
||||
* We could conceivable be called with a NULL commit
|
||||
* if our caller has a bug, and invokes graph_next_line()
|
||||
* immediately after graph_init(), without first calling
|
||||
* graph_update(). Return without outputting anything in this
|
||||
* case.
|
||||
*/
|
||||
if (!graph->commit)
|
||||
return;
|
||||
|
||||
/*
|
||||
* Output a padding row, that leaves all branch lines unchanged
|
||||
*/
|
||||
for (i = 0; i < graph->num_new_columns; i++) {
|
||||
strbuf_addstr(sb, "| ");
|
||||
}
|
||||
|
||||
graph_pad_horizontally(graph, sb);
|
||||
}
|
||||
|
||||
static void graph_output_skip_line(struct git_graph *graph, struct strbuf *sb)
|
||||
{
|
||||
/*
|
||||
* Output an ellipsis to indicate that a portion
|
||||
* of the graph is missing.
|
||||
*/
|
||||
strbuf_addstr(sb, "...");
|
||||
graph_pad_horizontally(graph, sb);
|
||||
|
||||
if (graph->num_parents >= 3)
|
||||
graph->state = GRAPH_PRE_COMMIT;
|
||||
else
|
||||
graph->state = GRAPH_COMMIT;
|
||||
}
|
||||
|
||||
static void graph_output_pre_commit_line(struct git_graph *graph,
|
||||
struct strbuf *sb)
|
||||
{
|
||||
int num_expansion_rows;
|
||||
int i, seen_this;
|
||||
|
||||
/*
|
||||
* This function formats a row that increases the space around a commit
|
||||
* with multiple parents, to make room for it. It should only be
|
||||
* called when there are 3 or more parents.
|
||||
*
|
||||
* We need 2 extra rows for every parent over 2.
|
||||
*/
|
||||
assert(graph->num_parents >= 3);
|
||||
num_expansion_rows = (graph->num_parents - 2) * 2;
|
||||
|
||||
/*
|
||||
* graph->expansion_row tracks the current expansion row we are on.
|
||||
* It should be in the range [0, num_expansion_rows - 1]
|
||||
*/
|
||||
assert(0 <= graph->expansion_row &&
|
||||
graph->expansion_row < num_expansion_rows);
|
||||
|
||||
/*
|
||||
* Output the row
|
||||
*/
|
||||
seen_this = 0;
|
||||
for (i = 0; i < graph->num_columns; i++) {
|
||||
struct column *col = &graph->columns[i];
|
||||
if (col->commit == graph->commit) {
|
||||
seen_this = 1;
|
||||
strbuf_addf(sb, "| %*s", graph->expansion_row, "");
|
||||
} else if (seen_this) {
|
||||
strbuf_addstr(sb, "\\ ");
|
||||
} else {
|
||||
strbuf_addstr(sb, "| ");
|
||||
}
|
||||
}
|
||||
|
||||
graph_pad_horizontally(graph, sb);
|
||||
|
||||
/*
|
||||
* Increment graph->expansion_row,
|
||||
* and move to state GRAPH_COMMIT if necessary
|
||||
*/
|
||||
graph->expansion_row++;
|
||||
if (graph->expansion_row >= num_expansion_rows)
|
||||
graph->state = GRAPH_COMMIT;
|
||||
}
|
||||
|
||||
void graph_output_commit_line(struct git_graph *graph, struct strbuf *sb)
|
||||
{
|
||||
int seen_this = 0;
|
||||
int i, j;
|
||||
|
||||
/*
|
||||
* Output the row containing this commit
|
||||
* Iterate up to and including graph->num_columns,
|
||||
* since the current commit may not be in any of the existing
|
||||
* columns. (This happens when the current commit doesn't have any
|
||||
* children that we have already processed.)
|
||||
*/
|
||||
seen_this = 0;
|
||||
for (i = 0; i <= graph->num_columns; i++) {
|
||||
struct commit *col_commit;
|
||||
if (i == graph->num_columns) {
|
||||
if (seen_this)
|
||||
break;
|
||||
col_commit = graph->commit;
|
||||
} else {
|
||||
col_commit = graph->columns[i].commit;
|
||||
}
|
||||
|
||||
if (col_commit == graph->commit) {
|
||||
seen_this = 1;
|
||||
if (graph->num_parents > 1)
|
||||
strbuf_addch(sb, 'M');
|
||||
else
|
||||
strbuf_addch(sb, '*');
|
||||
|
||||
if (graph->num_parents < 2)
|
||||
strbuf_addch(sb, ' ');
|
||||
else if (graph->num_parents == 2)
|
||||
strbuf_addstr(sb, " ");
|
||||
else {
|
||||
int num_dashes =
|
||||
((graph->num_parents - 2) * 2) - 1;
|
||||
for (j = 0; j < num_dashes; j++)
|
||||
strbuf_addch(sb, '-');
|
||||
strbuf_addstr(sb, ". ");
|
||||
}
|
||||
} else if (seen_this && (graph->num_parents > 1)) {
|
||||
strbuf_addstr(sb, "\\ ");
|
||||
} else {
|
||||
strbuf_addstr(sb, "| ");
|
||||
}
|
||||
}
|
||||
|
||||
graph_pad_horizontally(graph, sb);
|
||||
|
||||
/*
|
||||
* Update graph->state
|
||||
*/
|
||||
if (graph->num_parents > 1)
|
||||
graph->state = GRAPH_POST_MERGE;
|
||||
else if (graph_is_mapping_correct(graph))
|
||||
graph->state = GRAPH_PADDING;
|
||||
else
|
||||
graph->state = GRAPH_COLLAPSING;
|
||||
}
|
||||
|
||||
void graph_output_post_merge_line(struct git_graph *graph, struct strbuf *sb)
|
||||
{
|
||||
int seen_this = 0;
|
||||
int i, j;
|
||||
|
||||
/*
|
||||
* Output the post-merge row
|
||||
*/
|
||||
for (i = 0; i <= graph->num_columns; i++) {
|
||||
struct commit *col_commit;
|
||||
if (i == graph->num_columns) {
|
||||
if (seen_this)
|
||||
break;
|
||||
col_commit = graph->commit;
|
||||
} else {
|
||||
col_commit = graph->columns[i].commit;
|
||||
}
|
||||
|
||||
if (col_commit == graph->commit) {
|
||||
seen_this = 1;
|
||||
strbuf_addch(sb, '|');
|
||||
for (j = 0; j < graph->num_parents - 1; j++)
|
||||
strbuf_addstr(sb, "\\ ");
|
||||
if (graph->num_parents == 2)
|
||||
strbuf_addch(sb, ' ');
|
||||
} else if (seen_this && (graph->num_parents > 2)) {
|
||||
strbuf_addstr(sb, "\\ ");
|
||||
} else {
|
||||
strbuf_addstr(sb, "| ");
|
||||
}
|
||||
}
|
||||
|
||||
graph_pad_horizontally(graph, sb);
|
||||
|
||||
/*
|
||||
* Update graph->state
|
||||
*/
|
||||
if (graph_is_mapping_correct(graph))
|
||||
graph->state = GRAPH_PADDING;
|
||||
else
|
||||
graph->state = GRAPH_COLLAPSING;
|
||||
}
|
||||
|
||||
void graph_output_collapsing_line(struct git_graph *graph, struct strbuf *sb)
|
||||
{
|
||||
int i;
|
||||
int *tmp_mapping;
|
||||
|
||||
/*
|
||||
* Clear out the new_mapping array
|
||||
*/
|
||||
for (i = 0; i < graph->mapping_size; i++)
|
||||
graph->new_mapping[i] = -1;
|
||||
|
||||
for (i = 0; i < graph->mapping_size; i++) {
|
||||
int target = graph->mapping[i];
|
||||
if (target < 0)
|
||||
continue;
|
||||
|
||||
/*
|
||||
* Since update_columns() always inserts the leftmost
|
||||
* column first, each branch's target location should
|
||||
* always be either its current location or to the left of
|
||||
* its current location.
|
||||
*
|
||||
* We never have to move branches to the right. This makes
|
||||
* the graph much more legible, since whenever branches
|
||||
* cross, only one is moving directions.
|
||||
*/
|
||||
assert(target * 2 <= i);
|
||||
|
||||
if (target * 2 == i) {
|
||||
/*
|
||||
* This column is already in the
|
||||
* correct place
|
||||
*/
|
||||
assert(graph->new_mapping[i] == -1);
|
||||
graph->new_mapping[i] = target;
|
||||
} else if (graph->new_mapping[i - 1] < 0) {
|
||||
/*
|
||||
* Nothing is to the left.
|
||||
* Move to the left by one
|
||||
*/
|
||||
graph->new_mapping[i - 1] = target;
|
||||
} else if (graph->new_mapping[i - 1] == target) {
|
||||
/*
|
||||
* There is a branch line to our left
|
||||
* already, and it is our target. We
|
||||
* combine with this line, since we share
|
||||
* the same parent commit.
|
||||
*
|
||||
* We don't have to add anything to the
|
||||
* output or new_mapping, since the
|
||||
* existing branch line has already taken
|
||||
* care of it.
|
||||
*/
|
||||
} else {
|
||||
/*
|
||||
* There is a branch line to our left,
|
||||
* but it isn't our target. We need to
|
||||
* cross over it.
|
||||
*
|
||||
* The space just to the left of this
|
||||
* branch should always be empty.
|
||||
*/
|
||||
assert(graph->new_mapping[i - 1] > target);
|
||||
assert(graph->new_mapping[i - 2] < 0);
|
||||
graph->new_mapping[i - 2] = target;
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
* The new mapping may be 1 smaller than the old mapping
|
||||
*/
|
||||
if (graph->new_mapping[graph->mapping_size - 1] < 0)
|
||||
graph->mapping_size--;
|
||||
|
||||
/*
|
||||
* Output out a line based on the new mapping info
|
||||
*/
|
||||
for (i = 0; i < graph->mapping_size; i++) {
|
||||
int target = graph->new_mapping[i];
|
||||
if (target < 0)
|
||||
strbuf_addch(sb, ' ');
|
||||
else if (target * 2 == i)
|
||||
strbuf_addch(sb, '|');
|
||||
else
|
||||
strbuf_addch(sb, '/');
|
||||
}
|
||||
|
||||
graph_pad_horizontally(graph, sb);
|
||||
|
||||
/*
|
||||
* Swap mapping and new_mapping
|
||||
*/
|
||||
tmp_mapping = graph->mapping;
|
||||
graph->mapping = graph->new_mapping;
|
||||
graph->new_mapping = tmp_mapping;
|
||||
|
||||
/*
|
||||
* If graph->mapping indicates that all of the branch lines
|
||||
* are already in the correct positions, we are done.
|
||||
* Otherwise, we need to collapse some branch lines together.
|
||||
*/
|
||||
if (graph_is_mapping_correct(graph))
|
||||
graph->state = GRAPH_PADDING;
|
||||
}
|
||||
|
||||
int graph_next_line(struct git_graph *graph, struct strbuf *sb)
|
||||
{
|
||||
switch (graph->state) {
|
||||
case GRAPH_PADDING:
|
||||
graph_output_padding_line(graph, sb);
|
||||
return 0;
|
||||
case GRAPH_SKIP:
|
||||
graph_output_skip_line(graph, sb);
|
||||
return 0;
|
||||
case GRAPH_PRE_COMMIT:
|
||||
graph_output_pre_commit_line(graph, sb);
|
||||
return 0;
|
||||
case GRAPH_COMMIT:
|
||||
graph_output_commit_line(graph, sb);
|
||||
return 1;
|
||||
case GRAPH_POST_MERGE:
|
||||
graph_output_post_merge_line(graph, sb);
|
||||
return 0;
|
||||
case GRAPH_COLLAPSING:
|
||||
graph_output_collapsing_line(graph, sb);
|
||||
return 0;
|
||||
}
|
||||
|
||||
assert(0);
|
||||
return 0;
|
||||
}
|
||||
|
||||
void graph_padding_line(struct git_graph *graph, struct strbuf *sb)
|
||||
{
|
||||
int i, j;
|
||||
|
||||
if (graph->state != GRAPH_COMMIT) {
|
||||
graph_next_line(graph, sb);
|
||||
return;
|
||||
}
|
||||
|
||||
/*
|
||||
* Output the row containing this commit
|
||||
* Iterate up to and including graph->num_columns,
|
||||
* since the current commit may not be in any of the existing
|
||||
* columns. (This happens when the current commit doesn't have any
|
||||
* children that we have already processed.)
|
||||
*/
|
||||
for (i = 0; i < graph->num_columns; i++) {
|
||||
struct commit *col_commit = graph->columns[i].commit;
|
||||
if (col_commit == graph->commit) {
|
||||
strbuf_addch(sb, '|');
|
||||
|
||||
if (graph->num_parents < 3)
|
||||
strbuf_addch(sb, ' ');
|
||||
else {
|
||||
int num_spaces = ((graph->num_parents - 2) * 2);
|
||||
for (j = 0; j < num_spaces; j++)
|
||||
strbuf_addch(sb, ' ');
|
||||
}
|
||||
} else {
|
||||
strbuf_addstr(sb, "| ");
|
||||
}
|
||||
}
|
||||
|
||||
graph_pad_horizontally(graph, sb);
|
||||
}
|
||||
|
||||
int graph_is_commit_finished(struct git_graph const *graph)
|
||||
{
|
||||
return (graph->state == GRAPH_PADDING);
|
||||
}
|
||||
|
||||
void graph_show_commit(struct git_graph *graph)
|
||||
{
|
||||
struct strbuf msgbuf;
|
||||
int shown_commit_line = 0;
|
||||
|
||||
if (!graph)
|
||||
return;
|
||||
|
||||
strbuf_init(&msgbuf, 0);
|
||||
|
||||
while (!shown_commit_line) {
|
||||
shown_commit_line = graph_next_line(graph, &msgbuf);
|
||||
fwrite(msgbuf.buf, sizeof(char), msgbuf.len, stdout);
|
||||
if (!shown_commit_line)
|
||||
putchar('\n');
|
||||
strbuf_setlen(&msgbuf, 0);
|
||||
}
|
||||
|
||||
strbuf_release(&msgbuf);
|
||||
}
|
||||
|
||||
void graph_show_oneline(struct git_graph *graph)
|
||||
{
|
||||
struct strbuf msgbuf;
|
||||
|
||||
if (!graph)
|
||||
return;
|
||||
|
||||
strbuf_init(&msgbuf, 0);
|
||||
graph_next_line(graph, &msgbuf);
|
||||
fwrite(msgbuf.buf, sizeof(char), msgbuf.len, stdout);
|
||||
strbuf_release(&msgbuf);
|
||||
}
|
||||
|
||||
void graph_show_padding(struct git_graph *graph)
|
||||
{
|
||||
struct strbuf msgbuf;
|
||||
|
||||
if (!graph)
|
||||
return;
|
||||
|
||||
strbuf_init(&msgbuf, 0);
|
||||
graph_padding_line(graph, &msgbuf);
|
||||
fwrite(msgbuf.buf, sizeof(char), msgbuf.len, stdout);
|
||||
strbuf_release(&msgbuf);
|
||||
}
|
||||
|
||||
int graph_show_remainder(struct git_graph *graph)
|
||||
{
|
||||
struct strbuf msgbuf;
|
||||
int shown = 0;
|
||||
|
||||
if (!graph)
|
||||
return 0;
|
||||
|
||||
if (graph_is_commit_finished(graph))
|
||||
return 0;
|
||||
|
||||
strbuf_init(&msgbuf, 0);
|
||||
for (;;) {
|
||||
graph_next_line(graph, &msgbuf);
|
||||
fwrite(msgbuf.buf, sizeof(char), msgbuf.len, stdout);
|
||||
strbuf_setlen(&msgbuf, 0);
|
||||
shown = 1;
|
||||
|
||||
if (!graph_is_commit_finished(graph))
|
||||
putchar('\n');
|
||||
else
|
||||
break;
|
||||
}
|
||||
strbuf_release(&msgbuf);
|
||||
|
||||
return shown;
|
||||
}
|
||||
|
||||
|
||||
void graph_show_strbuf(struct git_graph *graph, struct strbuf const *sb)
|
||||
{
|
||||
char *p;
|
||||
|
||||
if (!graph) {
|
||||
fwrite(sb->buf, sizeof(char), sb->len, stdout);
|
||||
return;
|
||||
}
|
||||
|
||||
/*
|
||||
* Print the strbuf line by line,
|
||||
* and display the graph info before each line but the first.
|
||||
*/
|
||||
p = sb->buf;
|
||||
while (p) {
|
||||
size_t len;
|
||||
char *next_p = strchr(p, '\n');
|
||||
if (next_p) {
|
||||
next_p++;
|
||||
len = next_p - p;
|
||||
} else {
|
||||
len = (sb->buf + sb->len) - p;
|
||||
}
|
||||
fwrite(p, sizeof(char), len, stdout);
|
||||
if (next_p && *next_p != '\0')
|
||||
graph_show_oneline(graph);
|
||||
p = next_p;
|
||||
}
|
||||
}
|
||||
|
||||
void graph_show_commit_msg(struct git_graph *graph,
|
||||
struct strbuf const *sb)
|
||||
{
|
||||
int newline_terminated;
|
||||
|
||||
if (!graph) {
|
||||
/*
|
||||
* If there's no graph, just print the message buffer.
|
||||
*
|
||||
* The message buffer for CMIT_FMT_ONELINE and
|
||||
* CMIT_FMT_USERFORMAT are already missing a terminating
|
||||
* newline. All of the other formats should have it.
|
||||
*/
|
||||
fwrite(sb->buf, sizeof(char), sb->len, stdout);
|
||||
return;
|
||||
}
|
||||
|
||||
newline_terminated = (sb->len && sb->buf[sb->len - 1] == '\n');
|
||||
|
||||
/*
|
||||
* Show the commit message
|
||||
*/
|
||||
graph_show_strbuf(graph, sb);
|
||||
|
||||
/*
|
||||
* If there is more output needed for this commit, show it now
|
||||
*/
|
||||
if (!graph_is_commit_finished(graph)) {
|
||||
/*
|
||||
* If sb doesn't have a terminating newline, print one now,
|
||||
* so we can start the remainder of the graph output on a
|
||||
* new line.
|
||||
*/
|
||||
if (!newline_terminated)
|
||||
putchar('\n');
|
||||
|
||||
graph_show_remainder(graph);
|
||||
|
||||
/*
|
||||
* If sb ends with a newline, our output should too.
|
||||
*/
|
||||
if (newline_terminated)
|
||||
putchar('\n');
|
||||
}
|
||||
}
|
||||
121
graph.h
Normal file
121
graph.h
Normal file
@ -0,0 +1,121 @@
|
||||
#ifndef GRAPH_H
|
||||
#define GRAPH_H
|
||||
|
||||
/* A graph is a pointer to this opaque structure */
|
||||
struct git_graph;
|
||||
|
||||
/*
|
||||
* Create a new struct git_graph.
|
||||
* The graph should be freed with graph_release() when no longer needed.
|
||||
*/
|
||||
struct git_graph *graph_init();
|
||||
|
||||
/*
|
||||
* Destroy a struct git_graph and free associated memory.
|
||||
*/
|
||||
void graph_release(struct git_graph *graph);
|
||||
|
||||
/*
|
||||
* Update a git_graph with a new commit.
|
||||
* This will cause the graph to begin outputting lines for the new commit
|
||||
* the next time graph_next_line() is called.
|
||||
*
|
||||
* If graph_update() is called before graph_is_commit_finished() returns 1,
|
||||
* the next call to graph_next_line() will output an ellipsis ("...")
|
||||
* to indicate that a portion of the graph is missing.
|
||||
*/
|
||||
void graph_update(struct git_graph *graph, struct commit *commit);
|
||||
|
||||
/*
|
||||
* Output the next line for a graph.
|
||||
* This formats the next graph line into the specified strbuf. It is not
|
||||
* terminated with a newline.
|
||||
*
|
||||
* Returns 1 if the line includes the current commit, and 0 otherwise.
|
||||
* graph_next_line() will return 1 exactly once for each time
|
||||
* graph_update() is called.
|
||||
*/
|
||||
int graph_next_line(struct git_graph *graph, struct strbuf *sb);
|
||||
|
||||
/*
|
||||
* Output a padding line in the graph.
|
||||
* This is similar to graph_next_line(). However, it is guaranteed to
|
||||
* never print the current commit line. Instead, if the commit line is
|
||||
* next, it will simply output a line of vertical padding, extending the
|
||||
* branch lines downwards, but leaving them otherwise unchanged.
|
||||
*/
|
||||
void graph_padding_line(struct git_graph *graph, struct strbuf *sb);
|
||||
|
||||
/*
|
||||
* Determine if a graph has finished outputting lines for the current
|
||||
* commit.
|
||||
*
|
||||
* Returns 1 if graph_next_line() needs to be called again before
|
||||
* graph_update() should be called. Returns 0 if no more lines are needed
|
||||
* for this commit. If 0 is returned, graph_next_line() may still be
|
||||
* called without calling graph_update(), and it will merely output
|
||||
* appropriate "vertical padding" in the graph.
|
||||
*/
|
||||
int graph_is_commit_finished(struct git_graph const *graph);
|
||||
|
||||
|
||||
/*
|
||||
* graph_show_*: helper functions for printing to stdout
|
||||
*/
|
||||
|
||||
|
||||
/*
|
||||
* If the graph is non-NULL, print the history graph to stdout,
|
||||
* up to and including the line containing this commit.
|
||||
* Does not print a terminating newline on the last line.
|
||||
*/
|
||||
void graph_show_commit(struct git_graph *graph);
|
||||
|
||||
/*
|
||||
* If the graph is non-NULL, print one line of the history graph to stdout.
|
||||
* Does not print a terminating newline on the last line.
|
||||
*/
|
||||
void graph_show_oneline(struct git_graph *graph);
|
||||
|
||||
/*
|
||||
* If the graph is non-NULL, print one line of vertical graph padding to
|
||||
* stdout. Does not print a terminating newline on the last line.
|
||||
*/
|
||||
void graph_show_padding(struct git_graph *graph);
|
||||
|
||||
/*
|
||||
* If the graph is non-NULL, print the rest of the history graph for this
|
||||
* commit to stdout. Does not print a terminating newline on the last line.
|
||||
*/
|
||||
int graph_show_remainder(struct git_graph *graph);
|
||||
|
||||
/*
|
||||
* Print a strbuf to stdout. If the graph is non-NULL, all lines but the
|
||||
* first will be prefixed with the graph output.
|
||||
*
|
||||
* If the strbuf ends with a newline, the output will end after this
|
||||
* newline. A new graph line will not be printed after the final newline.
|
||||
* If the strbuf is empty, no output will be printed.
|
||||
*
|
||||
* Since the first line will not include the graph ouput, the caller is
|
||||
* responsible for printing this line's graph (perhaps via
|
||||
* graph_show_commit() or graph_show_oneline()) before calling
|
||||
* graph_show_strbuf().
|
||||
*/
|
||||
void graph_show_strbuf(struct git_graph *graph, struct strbuf const *sb);
|
||||
|
||||
/*
|
||||
* Print a commit message strbuf and the remainder of the graph to stdout.
|
||||
*
|
||||
* This is similar to graph_show_strbuf(), but it always prints the
|
||||
* remainder of the graph.
|
||||
*
|
||||
* If the strbuf ends with a newline, the output printed by
|
||||
* graph_show_commit_msg() will end with a newline. If the strbuf is
|
||||
* missing a terminating newline (including if it is empty), the output
|
||||
* printed by graph_show_commit_msg() will also be missing a terminating
|
||||
* newline.
|
||||
*/
|
||||
void graph_show_commit_msg(struct git_graph *graph, struct strbuf const *sb);
|
||||
|
||||
#endif /* GRAPH_H */
|
||||
Loading…
Reference in New Issue
Block a user