So how well are we doing lately?

Git v1.8.2 has 630+ non-merge commits since v1.8.1 release.

Averaged over time, the impact of each individual commit is about the same (because we reject an oversized patch that does too many unrelated things and have the submitter split it into multiple patches), so if one release cycle has twice the non-merge commits compared to another cycle, we can say it was about twice as busy.

But from time to time, it is good to measure our progress with different metrics to see how different metrics correlate with each other.

The table at the end lists how long each release cycle lasted, how many non-merge commits we had in the cycle and in each day in the cycle and how many lines of code (counting only *.[ch] source files) were affected in the cycle and in each day in the cycle. The "lines of code affected" are counted in two different ways.

We can see that the latest release cycle was relatively active, while the previous cycle that overlapped the year-end holidays was slow, both from commit count (348 vs 635) and one modification count (2921 vs 5881), but not with the other modification count (6047 vs 6355).

The "modified" number is computed with "git blame -C -C -C -w" to track line-level movements, while the "modified2" number is computed with "git diff -M" which is less accurate when the code gets refactored, and that is where the above apparent discrepancy comes from.

The v1.8.1 cycle has a lot smaller real changes (measured by "git blame") than apparent changes (measured by "git diff -M") because it created two new files by splitting two existing files.  The measurement based on "git blame -C" knows to consider bulk movement of lines by such a change as a non-event, but it will show up in "git diff --stat -M" output as a large change.

 builtin/fetch-pack.c | 950 +-------------------------------------------------------------
 builtin/send-pack.c  | 333 ----------------------
 fetch-pack.c         | 951 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 send-pack.c          | 344 +++++++++++++++++++++++

So the "modified" number is a better indication of how much actual work is done, but it is painfully expensive to compute.

I'll later explain how to use blame and diff to compute these numbers for your projects in a separate post.

release	days	commits	commit/day	modified	mod/day	modified2	mod2/day
v1.5.0	90	1448	16.08	12369	137.43	13640	151.55
v1.5.1	49	643	13.12	7822	159.63	8213	167.61
v1.5.2	46	575	12.50	7604	165.30	8273	179.84
v1.5.3	104	1322	12.71	8081	77.70	9538	91.71
v1.5.4	152	1595	10.49	21422	140.93	24934	164.03
v1.5.5	66	729	11.04	9790	148.33	12172	184.42
v1.5.6	71	569	8.01	7091	99.87	8354	117.66
v1.6.0	59	731	12.38	16709	283.20	19481	330.18
v1.6.1	129	1033	8.00	10316	79.96	14262	110.55
v1.6.2	69	499	7.23	4835	70.07	5322	77.13
v1.6.3	63	692	10.98	6642	105.42	8687	137.88
v1.6.4	83	500	6.02	13571	163.50	14296	172.24
v1.6.5	72	412	5.72	5018	69.69	5623	78.09
v1.6.6	74	483	6.52	6011	81.22	6730	90.94
v1.7.0	51	569	11.15	7698	150.94	8635	169.31
v1.7.1	70	477	6.81	5830	83.28	6558	93.68
v1.7.2	88	532	6.04	5615	63.80	6380	72.50
v1.7.3	59	481	8.15	20753	351.74	21473	363.94
v1.7.4	134	746	5.56	8527	63.63	9744	72.71
v1.7.5	83	548	6.60	6766	81.51	7543	90.87
v1.7.6	63	427	6.77	3962	62.88	4351	69.06
v1.7.7	96	563	5.86	8928	93.00	10107	105.28
v1.7.8	62	426	6.87	5098	82.22	5463	88.11
v1.7.9	56	391	6.98	6338	113.17	6886	122.96
v1.7.10	69	440	6.37	5051	73.20	7271	105.37
v1.7.11	72	652	9.05	7354	102.13	8863	123.09
v1.7.12	63	382	6.06	3060	48.57	3411	54.14
v1.8.0	62	497	8.01	5611	90.50	6037	97.37
v1.8.1	71	348	4.90	2921	41.14	6047	85.16
v1.8.2	71	635	8.94	5881	82.83	6599	92.94