Re: [PATCH v2 01/14] commit-slab.h: code split

[Junio C Hamano]

Nguyễn Thái Ngọc Duy   writes:

> The struct declaration and implementation macros are moved to
> commit-slab-hdr.h and commit-slab-impl.h respectively. This right now
> is not needed for current users but if we share a commit-slab for
> multiple files, we need something better than the current structure.

"something better" needs to be replaced with something better for it
to be worth being there.  In other words, say why you want to avoid
including the part you moved to *-impl.h everywhere.

I also think you want to rename s/-hdr.h/-decl.h/ or something to
avoid sounding silly by repeating "header" twice in the name.

> Signed-off-by: Nguyễn Thái Ngọc Duy 
> ---
>  commit-slab-hdr.h  |  30 
>  commit-slab-impl.h |  91 +++
>  commit-slab.h  | 115 +++--
>  3 files changed, 127 insertions(+), 109 deletions(-)
>  create mode 100644 commit-slab-hdr.h
>  create mode 100644 commit-slab-impl.h

"git blame" tells me that the new two files consist mostly of the
material from commit-slab.h moved verbatim, which is assuring ;-).

[PATCH v2 01/14] commit-slab.h: code split

[Nguyễn Thái Ngọc Duy]

The struct declaration and implementation macros are moved to
commit-slab-hdr.h and commit-slab-impl.h respectively. This right now
is not needed for current users but if we share a commit-slab for
multiple files, we need something better than the current structure.

Signed-off-by: Nguyễn Thái Ngọc Duy 
---
 commit-slab-hdr.h  |  30 
 commit-slab-impl.h |  91 +++
 commit-slab.h  | 115 +++--
 3 files changed, 127 insertions(+), 109 deletions(-)
 create mode 100644 commit-slab-hdr.h
 create mode 100644 commit-slab-impl.h

diff --git a/commit-slab-hdr.h b/commit-slab-hdr.h
new file mode 100644
index 00..fb5220fb7d
--- /dev/null
+++ b/commit-slab-hdr.h
@@ -0,0 +1,30 @@
+#ifndef COMMIT_SLAB_HDR_H
+#define COMMIT_SLAB_HDR_H
+
+/* allocate ~512kB at once, allowing for malloc overhead */
+#ifndef COMMIT_SLAB_SIZE
+#define COMMIT_SLAB_SIZE (512*1024-32)
+#endif
+
+#define declare_commit_slab(slabname, elemtype)\
+   \
+struct slabname {  \
+   unsigned slab_size; \
+   unsigned stride;\
+   unsigned slab_count;\
+   elemtype **slab;\
+}
+
+/*
+ * Statically initialize a commit slab named "var". Note that this
+ * evaluates "stride" multiple times! Example:
+ *
+ *   struct indegree indegrees = COMMIT_SLAB_INIT(1, indegrees);
+ *
+ */
+#define COMMIT_SLAB_INIT(stride, var) { \
+   COMMIT_SLAB_SIZE / sizeof(**((var).slab)) / (stride), \
+   (stride), 0, NULL \
+}
+
+#endif /* COMMIT_SLAB_HDR_H */
diff --git a/commit-slab-impl.h b/commit-slab-impl.h
new file mode 100644
index 00..234d9ee5f0
--- /dev/null
+++ b/commit-slab-impl.h
@@ -0,0 +1,91 @@
+#ifndef COMMIT_SLAB_IMPL_H
+#define COMMIT_SLAB_IMPL_H
+
+#define MAYBE_UNUSED __attribute__((__unused__))
+
+#define implement_commit_slab(slabname, elemtype)  \
+   \
+static int stat_ ##slabname## realloc; \
+   \
+static MAYBE_UNUSED void init_ ##slabname## _with_stride(struct slabname *s, \
+  unsigned stride) \
+{  \
+   unsigned int elem_size; \
+   if (!stride)\
+   stride = 1; \
+   s->stride = stride; \
+   elem_size = sizeof(elemtype) * stride;  \
+   s->slab_size = COMMIT_SLAB_SIZE / elem_size;\
+   s->slab_count = 0;  \
+   s->slab = NULL; \
+}  \
+   \
+static MAYBE_UNUSED void init_ ##slabname(struct slabname *s)  \
+{  \
+   init_ ##slabname## _with_stride(s, 1);  \
+}  \
+   \
+static MAYBE_UNUSED void clear_ ##slabname(struct slabname *s) \
+{  \
+   unsigned int i; \
+   for (i = 0; i < s->slab_count; i++) \
+   free(s->slab[i]);   \
+   s->slab_count = 0;  \
+   FREE_AND_NULL(s->slab); \
+}  \
+   \
+static MAYBE_UNUSED elemtype *slabname## _at_peek(struct slabname *s,  \
+ const struct commit *c, \
+ int add_if_missing)   \
+{  \
+   unsigned int nth_slab, nth_slot;\
+   \
+   nth_slab = c->index / s->slab_size; \
+   nth_slot = c->index %