Mailing List Archive

Author: phk
Date: 2007-08-06 10:07:18 +0200 (Mon, 06 Aug 2007)
New Revision: 1803

Modified:
trunk/varnish-cache/include/vcl.h
trunk/varnish-cache/lib/libvcl/vcc_action.c
trunk/varnish-cache/lib/libvcl/vcc_compile.c
trunk/varnish-cache/lib/libvcl/vcc_compile.h
trunk/varnish-cache/lib/libvcl/vcc_fixed_token.c
trunk/varnish-cache/lib/libvcl/vcc_gen_fixed_token.tcl
Log:
Have the VCL compiler provide a hint about the worst case number of
operations on the req.hash variable.

It is only a hint, because it merely counts how many times the parser
saw something being added to the req.hash variable. If the operation
was in a subroutine which was called multiple times, the hint will not
reflect the number of actual operations.

For now we will deal with that at runtime, at the expense of a
failed transaction every time we run short. If this becomes an issue,
an extensive topological analysis of the VCL program can give us
a definitive count.



Modified: trunk/varnish-cache/include/vcl.h
===================================================================
--- trunk/varnish-cache/include/vcl.h 2007-08-05 21:06:41 UTC (rev 1802)
+++ trunk/varnish-cache/include/vcl.h 2007-08-06 08:07:18 UTC (rev 1803)
@@ -26,6 +26,8 @@
const char **srcname;
const char **srcbody;

+ unsigned nhashcount;
+
void *priv;

vcl_init_f *init_func;

Modified: trunk/varnish-cache/lib/libvcl/vcc_action.c
===================================================================
--- trunk/varnish-cache/lib/libvcl/vcc_action.c 2007-08-05 21:06:41 UTC (rev 1802)
+++ trunk/varnish-cache/lib/libvcl/vcc_action.c 2007-08-06 08:07:18 UTC (rev 1803)
@@ -209,6 +209,12 @@
return;
}
Fb(tl, 0, ");\n");
+ /*
+ * We count the number of operations on the req.hash
+ * variable, so that varnishd can preallocate the worst case
+ * number of slots for composing the hash string.
+ */
+ tl->nhashcount++;
break;
case STRING:
if (tl->t->tok != '=') {

Modified: trunk/varnish-cache/lib/libvcl/vcc_compile.c
===================================================================
--- trunk/varnish-cache/lib/libvcl/vcc_compile.c 2007-08-05 21:06:41 UTC (rev 1802)
+++ trunk/varnish-cache/lib/libvcl/vcc_compile.c 2007-08-06 08:07:18 UTC (rev 1803)
@@ -348,6 +348,7 @@
Fc(tl, 0, "\t.nsrc = %u,\n", tl->nsources);
Fc(tl, 0, "\t.srcname = srcname,\n");
Fc(tl, 0, "\t.srcbody = srcbody,\n");
+ Fc(tl, 0, "\t.nhashcount = %u,\n", tl->nhashcount);
#define VCL_RET_MAC(l,u,b,n)
#define VCL_MET_MAC(l,u,b) \
Fc(tl, 0, "\t." #l "_func = VGC_function_vcl_" #l ",\n");

Modified: trunk/varnish-cache/lib/libvcl/vcc_compile.h
===================================================================
--- trunk/varnish-cache/lib/libvcl/vcc_compile.h 2007-08-05 21:06:41 UTC (rev 1802)
+++ trunk/varnish-cache/lib/libvcl/vcc_compile.h 2007-08-06 08:07:18 UTC (rev 1803)
@@ -83,6 +83,7 @@
struct proc *mprocs[N_METHODS];

unsigned recnt;
+ unsigned nhashcount;
};

enum var_type {

Modified: trunk/varnish-cache/lib/libvcl/vcc_fixed_token.c
===================================================================
--- trunk/varnish-cache/lib/libvcl/vcc_fixed_token.c 2007-08-05 21:06:41 UTC (rev 1802)
+++ trunk/varnish-cache/lib/libvcl/vcc_fixed_token.c 2007-08-06 08:07:18 UTC (rev 1803)
@@ -338,6 +338,8 @@
vsb_cat(sb, " const char **srcname;\n");
vsb_cat(sb, " const char **srcbody;\n");
vsb_cat(sb, "\n");
+ vsb_cat(sb, " unsigned nhashcount;\n");
+ vsb_cat(sb, "\n");
vsb_cat(sb, " void *priv;\n");
vsb_cat(sb, "\n");
vsb_cat(sb, " vcl_init_f *init_func;\n");

Modified: trunk/varnish-cache/lib/libvcl/vcc_gen_fixed_token.tcl
===================================================================
--- trunk/varnish-cache/lib/libvcl/vcc_gen_fixed_token.tcl 2007-08-05 21:06:41 UTC (rev 1802)
+++ trunk/varnish-cache/lib/libvcl/vcc_gen_fixed_token.tcl 2007-08-06 08:07:18 UTC (rev 1803)
@@ -142,6 +142,8 @@
const char **srcname;
const char **srcbody;

+ unsigned nhashcount;
+
void *priv;

vcl_init_f *init_func;