Patchwork [4,of,7,V5] sparse-revlog: add a `trim_endidx` function in C

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Submitter Boris Feld
Date Nov. 22, 2018, 6:08 p.m.
Message ID <cc7132133f0e391b5398.1542910086@localhost.localdomain>
Download mbox | patch
Permalink /patch/36719/
State Accepted
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Comments

Boris Feld - Nov. 22, 2018, 6:08 p.m.
# HG changeset patch
# User Boris Feld <boris.feld@octobus.net>
# Date 1541785523 -3600
#      Fri Nov 09 18:45:23 2018 +0100
# Node ID cc7132133f0e391b53985b4d08072304032fd444
# Parent  4ad3891a07ed83cda837db8d0cbe285ebb377869
# EXP-Topic sparse-perf
# Available At https://bitbucket.org/octobus/mercurial-devel/
#              hg pull https://bitbucket.org/octobus/mercurial-devel/ -r cc7132133f0e
sparse-revlog: add a `trim_endidx` function in C

We are about to implement a native version of `slicechunktodensity`. For
clarity, we introduce the helper functions first.

This function implement a subpart of the python function `_trimchunk` in
`mercurial/revlogutils/deltas.py`. Handling of actual Python objects is left
to the caller function.
Yuya Nishihara - Nov. 24, 2018, 1:23 a.m.
On Thu, 22 Nov 2018 19:08:06 +0100, Boris Feld wrote:
> # HG changeset patch
> # User Boris Feld <boris.feld@octobus.net>
> # Date 1541785523 -3600
> #      Fri Nov 09 18:45:23 2018 +0100
> # Node ID cc7132133f0e391b53985b4d08072304032fd444
> # Parent  4ad3891a07ed83cda837db8d0cbe285ebb377869
> # EXP-Topic sparse-perf
> # Available At https://bitbucket.org/octobus/mercurial-devel/
> #              hg pull https://bitbucket.org/octobus/mercurial-devel/ -r cc7132133f0e
> sparse-revlog: add a `trim_endidx` function in C
> 
> We are about to implement a native version of `slicechunktodensity`. For
> clarity, we introduce the helper functions first.
> 
> This function implement a subpart of the python function `_trimchunk` in
> `mercurial/revlogutils/deltas.py`. Handling of actual Python objects is left
> to the caller function.
> 
> diff --git a/mercurial/cext/revlog.c b/mercurial/cext/revlog.c
> --- a/mercurial/cext/revlog.c
> +++ b/mercurial/cext/revlog.c
> @@ -1077,6 +1077,24 @@ index_segment_span(indexObject *self, Py
>  	return (end_offset - start_offset) + (int64_t)end_size;
>  }
>  
> +/* returns revs[startidx:endidx] without empty trailing revs */

The function doc isn't correct. Can you update as a follow up?

> +static Py_ssize_t trim_endidx(indexObject *self, Py_ssize_t *revs,
> +                              Py_ssize_t startidx, Py_ssize_t endidx)

I've changed *revs to const * to make it clear revs isn't an output variable.

> +{
> +	int length;
> +	while (endidx > 1 && endidx > startidx) {
> +		length = index_get_length(self, revs[endidx - 1]);
> +		if (length < 0) {
> +			return -1;
> +		}
> +		if (length != 0) {
> +			break;
> +		}
> +		endidx -= 1;
> +	}
> +	return endidx;
> +}

Patch

diff --git a/mercurial/cext/revlog.c b/mercurial/cext/revlog.c
--- a/mercurial/cext/revlog.c
+++ b/mercurial/cext/revlog.c
@@ -1077,6 +1077,24 @@  index_segment_span(indexObject *self, Py
 	return (end_offset - start_offset) + (int64_t)end_size;
 }
 
+/* returns revs[startidx:endidx] without empty trailing revs */
+static Py_ssize_t trim_endidx(indexObject *self, Py_ssize_t *revs,
+                              Py_ssize_t startidx, Py_ssize_t endidx)
+{
+	int length;
+	while (endidx > 1 && endidx > startidx) {
+		length = index_get_length(self, revs[endidx - 1]);
+		if (length < 0) {
+			return -1;
+		}
+		if (length != 0) {
+			break;
+		}
+		endidx -= 1;
+	}
+	return endidx;
+}
+
 static inline int nt_level(const char *node, Py_ssize_t level)
 {
 	int v = node[level >> 1];