upstream/haproxy
1
0
Fork 0
mirror of https://github.com/haproxy/haproxy.git synced 2026-04-15 21:59:41 -04:00
Code Issues Projects Releases Packages Wiki Activity Actions 3

MINOR: otel: added prefix-based variable scanning

Browse source 
Introduced an alternative variable scanning strategy that directly walked
the CEB tree of HAProxy's variable store instead of maintaining a separate
tracking buffer.

The Makefile auto-detected whether struct var carried a "name" member
by inspecting include/haproxy/vars-t.h and conditionally defined
USE_OTEL_VARS_NAME.  When enabled, the tracking buffer (flt_otel_ctx) and
its callback type were compiled out and replaced by direct tree walks.

flt_otel_vars_unset() walked the CEB tree for the resolved scope, removed
every variable whose normalized name matched the given prefix followed by
a dot, and adjusted the variable accounting.  flt_otel_vars_get()
performed the same prefix scan under a read lock, denormalized each
matching variable name back to its original OTel form, and assembled the
results into an otelc_text_map.

A helper flt_otel_vars_get_scope() was added to resolve scope name strings
("txn", "sess", "proc", "req", "res") to the corresponding HAProxy
variable store.  The set path skipped the tracking buffer update when
prefix scanning was available.
This commit is contained in:
Miroslav Zagorac 2026-02-11 06:55:44 +01:00 committed by William Lallemand
parent 2d6a15ac00
commit b1498910ec
3 changed files with 232 additions and 1 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

8
addons/otel/Makefile
View file

@ -65,6 +65,14 @@ OPTIONS_OBJS += \
ifneq ($(OTEL_USE_VARS:0=),)
OTEL_DEFINE += -DUSE_OTEL_VARS
OPTIONS_OBJS += addons/otel/src/vars.o
# Auto-detect whether struct var has a 'name' member. When present,
# prefix-based variable scanning can be used instead of the tracking
# buffer approach.
OTEL_VAR_HAS_NAME := $(shell awk '/^struct var \{/,/^\}/' include/haproxy/vars-t.h 2>/dev/null | grep -q '[*]name;' && echo 1)
ifneq ($(OTEL_VAR_HAS_NAME),)
OTEL_DEFINE += -DUSE_OTEL_VARS_NAME
endif
endif
OTEL_CFLAGS := $(OTEL_CFLAGS) -Iaddons/otel/include $(OTEL_DEFINE)

5
addons/otel/include/vars.h
View file

@ -4,10 +4,12 @@
#define _OTEL_VARS_H_
#define FLT_OTEL_VARS_SCOPE "txn"
#define FLT_OTEL_VAR_CTX_SIZE int8_t
#define FLT_OTEL_VAR_CHAR_DASH 'D'
#define FLT_OTEL_VAR_CHAR_SPACE 'S'
#ifndef USE_OTEL_VARS_NAME
# define FLT_OTEL_VAR_CTX_SIZE int8_t
/* Context buffer for storing a single variable value during iteration. */
struct flt_otel_ctx {
char value[BUFSIZ]; /* Variable value string. */
@ -16,6 +18,7 @@ struct flt_otel_ctx {
/* Callback type invoked for each context variable during iteration. */
typedef int (*flt_otel_ctx_loop_cb)(struct sample *, size_t, const char *, const char *, const char *, FLT_OTEL_VAR_CTX_SIZE, char **, void *);
#endif /* !USE_OTEL_VARS_NAME */
#ifndef DEBUG_OTEL

220
addons/otel/src/vars.c
View file

@ -31,6 +31,7 @@ static void flt_otel_vars_scope_dump(struct vars *vars, const char *scope)
if (vars == NULL)
return;
/* Lock the variable store for safe iteration. */
vars_rdlock(vars);
for (i = 0; i < VAR_NAME_ROOTS; i++) {
struct ceb_node *node = cebu64_imm_first(&(vars->name_root[i]));
@ -307,6 +308,8 @@ static inline void flt_otel_smp_init(struct stream *s, struct sample *smp, uint
}
#ifndef USE_OTEL_VARS_NAME
/***
* NAME
* flt_otel_smp_add - context variable name registration
@ -837,6 +840,221 @@ struct otelc_text_map *flt_otel_vars_get(struct stream *s, const char *scope, co
OTELC_RETURN_PTR(retptr);
}
#else
/***
* NAME
* flt_otel_vars_get_scope - resolve scope string to variable store
*
* SYNOPSIS
* static struct vars *flt_otel_vars_get_scope(struct stream *s, const char *scope)
*
* ARGUMENTS
* s - current stream
* scope - variable scope string ("proc", "sess", "txn", "req", "res")
*
* DESCRIPTION
* Resolves a scope name string to the corresponding HAProxy variable
* store for the given <stream>.
*
* RETURN VALUE
* Returns a pointer to the variable store, or NULL if the <scope>
* is unknown.
*/
static struct vars *flt_otel_vars_get_scope(struct stream *s, const char *scope)
{
if (strcmp(scope, "txn") == 0)
return &(s->vars_txn);
else if (strcmp(scope, "req") == 0)
return &(s->vars_reqres);
else if (strcmp(scope, "res") == 0)
return &(s->vars_reqres);
else if (strcmp(scope, "sess") == 0)
return &(s->sess->vars);
else if (strcmp(scope, "proc") == 0)
return &proc_vars;
return NULL;
}
/***
* NAME
* flt_otel_vars_unset - context variables bulk unset via prefix scan
*
* SYNOPSIS
* int flt_otel_vars_unset(struct stream *s, const char *scope, const char *prefix, uint opt, char **err)
*
* ARGUMENTS
* s - current stream
* scope - variable scope
* prefix - variable prefix
* opt - sample option flags
* err - indirect pointer to error message string
*
* DESCRIPTION
* Unsets all context variables whose name starts with the normalized
* <prefix> followed by a dot. Walks the CEB tree of the variable
* store for the given <scope> and removes each matching variable.
*
* RETURN VALUE
* Returns the number of variables removed, 0 if none found,
* or FLT_OTEL_RET_ERROR on failure.
*/
int flt_otel_vars_unset(struct stream *s, const char *scope, const char *prefix, uint opt, char **err)
{
struct vars *vars;
char norm_prefix[BUFSIZ];
unsigned int size = 0;
int prefix_len, retval = 0, i;
OTELC_FUNC("%p, \"%s\", \"%s\", %u, %p:%p", s, OTELC_STR_ARG(scope), OTELC_STR_ARG(prefix), opt, OTELC_DPTR_ARGS(err));
prefix_len = flt_otel_var_name(prefix, NULL, NULL, 0, norm_prefix, sizeof(norm_prefix), err);
if (prefix_len == FLT_OTEL_RET_ERROR)
OTELC_RETURN_INT(FLT_OTEL_RET_ERROR);
vars = flt_otel_vars_get_scope(s, scope);
if (vars == NULL)
OTELC_RETURN_INT(0);
/* Lock and iterate all variables, clearing those matching the prefix. */
vars_wrlock(vars);
for (i = 0; i < VAR_NAME_ROOTS; i++) {
struct ceb_node *node = cebu64_imm_first(&(vars->name_root[i]));
while (node != NULL) {
struct var *var = container_of(node, struct var, name_node);
struct ceb_node *next = cebu64_imm_next(&(vars->name_root[i]), node);
if ((var->name != NULL) &&
(strncmp(var->name, norm_prefix, prefix_len) == 0) &&
(var->name[prefix_len] == '.')) {
OTELC_DBG(NOTICE, "prefix unset '%s'", var->name);
size += var_clear(vars, var, 1);
retval++;
}
node = next;
}
}
vars_wrunlock(vars);
if (size > 0)
var_accounting_diff(vars, s->sess, s, -(int)size);
OTELC_RETURN_INT(retval);
}
/***
* NAME
* flt_otel_vars_get - context variables to text map via prefix scan
*
* SYNOPSIS
* struct otelc_text_map *flt_otel_vars_get(struct stream *s, const char *scope, const char *prefix, uint opt, char **err)
*
* ARGUMENTS
* s - current stream
* scope - variable scope
* prefix - variable prefix
* opt - sample option flags
* err - indirect pointer to error message string
*
* DESCRIPTION
* Reads all context variables whose name starts with the normalized
* <prefix> followed by a dot. Walks the CEB tree of the variable
* store for the given <scope>, denormalizes each matching variable
* name, and adds the key-value pair to the returned text map.
*
* RETURN VALUE
* Returns a pointer to the populated text map, or NULL if no
* variables are found.
*/
struct otelc_text_map *flt_otel_vars_get(struct stream *s, const char *scope, const char *prefix, uint opt, char **err)
{
struct vars *vars;
struct otelc_text_map *retptr = NULL;
char norm_prefix[BUFSIZ], otel_name[BUFSIZ];
int prefix_len, i;
OTELC_FUNC("%p, \"%s\", \"%s\", %u, %p:%p", s, OTELC_STR_ARG(scope), OTELC_STR_ARG(prefix), opt, OTELC_DPTR_ARGS(err));
prefix_len = flt_otel_var_name(prefix, NULL, NULL, 0, norm_prefix, sizeof(norm_prefix), err);
if (prefix_len == FLT_OTEL_RET_ERROR)
OTELC_RETURN_PTR(NULL);
vars = flt_otel_vars_get_scope(s, scope);
if (vars == NULL)
OTELC_RETURN_PTR(NULL);
/* Read-lock and collect all variables matching the prefix into a text map. */
vars_rdlock(vars);
for (i = 0; i < VAR_NAME_ROOTS; i++) {
struct ceb_node *node = cebu64_imm_first(&(vars->name_root[i]));
for ( ; node != NULL; node = cebu64_imm_next(&(vars->name_root[i]), node)) {
struct var *var = container_of(node, struct var, name_node);
const char *key;
int otel_name_len;
if ((var->name == NULL) ||
(strncmp(var->name, norm_prefix, prefix_len) != 0) ||
(var->name[prefix_len] != '.'))
continue;
/* Skip the "prefix." part to get the key name. */
key = var->name + prefix_len + 1;
otel_name_len = flt_otel_denormalize_name(key, otel_name, sizeof(otel_name), err);
if (otel_name_len == FLT_OTEL_RET_ERROR) {
FLT_OTEL_ERR("failed to reverse variable name, buffer too small");
break;
}
if ((var->data.type != SMP_T_STR) && (var->data.type != SMP_T_BIN)) {
OTELC_DBG(NOTICE, "skipping '%s', unsupported type %d", var->name, var->data.type);
continue;
}
OTELC_DBG(NOTICE, "'%s' -> '%.*s'", var->name, (int)b_data(&(var->data.u.str)), b_orig(&(var->data.u.str)));
if (retptr == NULL) {
retptr = OTELC_TEXT_MAP_NEW(NULL, 8);
if (retptr == NULL) {
FLT_OTEL_ERR("failed to create map data");
break;
}
}
if (OTELC_TEXT_MAP_ADD(retptr, otel_name, otel_name_len, b_orig(&(var->data.u.str)), b_data(&(var->data.u.str)), OTELC_TEXT_MAP_AUTO) == -1) {
FLT_OTEL_ERR("failed to add map data");
otelc_text_map_destroy(&retptr);
break;
}
}
}
vars_rdunlock(vars);
OTELC_TEXT_MAP_DUMP(retptr, "extracted variables");
if ((retptr != NULL) && (retptr->count == 0)) {
OTELC_DBG(NOTICE, "WARNING: no variables found");
otelc_text_map_destroy(&retptr);
}
OTELC_RETURN_PTR(retptr);
}
#endif /* USE_OTEL_VARS_NAME */
/***
* NAME
@ -938,8 +1156,10 @@ int flt_otel_var_set(struct stream *s, const char *scope, const char *prefix, co
retval = var_name_len;
#ifndef USE_OTEL_VARS_NAME
if (strcmp(scope, FLT_OTEL_VARS_SCOPE) == 0)
retval = flt_otel_ctx_set(s, scope, prefix, name, opt, err);
#endif
}
OTELC_RETURN_INT(retval);