Initial implementation of git save format

This saves the dive data into a git object repository instead of a
single XML file.

We create a git object tree with each dive as a separate file,
hierarchically by trip and date.

NOTE 1: This largely duplicates the XML saving code, because trying to
share it seemed just too painful: the logic is very similar, but the
details of the actual strings end up differing sufficiently that there
are tons of trivial differences.

The git save format is line-based with minimal quoting, while XML quotes
everything with either "<..\>" or using single quotes around attributes.

NOTE 2: You currently need a dummy "file" to save to, which points to
the real save location: the git repository and branch to be used.  We
should make this a config thing, but for testing, do something like
this:

	echo git /home/torvalds/scuba:linus > git-test

to create that git information file, and when you use "Save To" and
specify "git-test" as the file to save to, subsurface will use the new
git save logic to save to the branch "linus" in the repository found at
"/home/torvalds/scuba".

NOTE 3: The git save format uses just the git object directory, it does
*not* check out the result in any git working tree or index.  So after
you do a save, you can do

     git log -p linus

to see what actually happened in that branch, but it will not affect any
actual checked-out state in the repository.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/dive.h b/dive.h
index a36c6e4f4..a87d05d7d 100644
--- a/dive.h
+++ b/dive.h
@@ -685,6 +685,7 @@ extern void save_dives(const char *filename);
 extern void save_dives_logic(const char *filename, bool select_only);
 extern void save_dive(FILE *f, struct dive *dive);
 extern void export_dives_uddf(const char *filename, const bool selected);
+extern int git_save_dives(int fd, bool select_only);
 
 extern int subsurface_rename(const char *path, const char *newpath);
 extern int subsurface_open(const char *path, int oflags, mode_t mode);
@@ -723,6 +724,8 @@ extern void add_gas_switch_event(struct dive *dive, struct divecomputer *dc, int
 extern void add_event(struct divecomputer *dc, int time, int type, int flags, int value, const char *name);
 extern void per_cylinder_mean_depth(struct dive *dive, struct divecomputer *dc, int *mean, int *duration);
 extern int get_cylinder_index(struct dive *dive, struct event *ev);
+extern int nr_cylinders(struct dive *dive);
+extern int nr_weightsystems(struct dive *dive);
 
 /* UI related protopypes */