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perf(config): cache sys getenv #3670

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091c262
perf(config): cache sys getenv
morrisonlevi Feb 27, 2026
4630694
perf(config): avoid interim string copies
morrisonlevi Feb 27, 2026
29395b8
fix: zero name len test
morrisonlevi Feb 28, 2026
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76 changes: 38 additions & 38 deletions ext/otel_config.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -20,22 +20,22 @@ static void report_otel_cfg_telemetry_invalid(const char *otel_cfg, const char *
}
}

static bool get_otel_value(zai_str str, zai_env_buffer buf, bool pre_rinit) {
if (zai_getenv_ex(str, buf, pre_rinit) == ZAI_ENV_SUCCESS) {
static bool get_otel_value(zai_str str, zai_env_buffer *buf, bool pre_rinit) {
if (zai_getenv_ex(str, buf, pre_rinit, true) == ZAI_ENV_SUCCESS) {
return true;
}

zval *cfg = cfg_get_entry(str.ptr, str.len);
if (cfg) {
if (Z_TYPE_P(cfg) == IS_ARRAY) {
zval *val;
char *off = buf.ptr;
char *off = buf->ptr;
ZEND_HASH_FOREACH_VAL(Z_ARR_P(cfg), val) {
if (Z_TYPE_P(val) == IS_STRING) {
if (off - buf.ptr + Z_STRLEN_P(val) + 2 >= ZAI_ENV_MAX_BUFSIZ) {
if (off - buf->ptr + Z_STRLEN_P(val) + 2 >= ZAI_ENV_MAX_BUFSIZ) {
return false;
}
if (off != buf.ptr) {
if (off != buf->ptr) {
*off++ = ',';
}
memcpy(off, Z_STRVAL_P(val), Z_STRLEN_P(val));
Expand All @@ -46,29 +46,29 @@ static bool get_otel_value(zai_str str, zai_env_buffer buf, bool pre_rinit) {
} else if (Z_STRLEN_P(cfg) == 0 || Z_STRLEN_P(cfg) + 1 >= ZAI_ENV_MAX_BUFSIZ) {
return false;
} else {
memcpy(buf.ptr, Z_STRVAL_P(cfg), Z_STRLEN_P(cfg) + 1);
memcpy(buf->ptr, Z_STRVAL_P(cfg), Z_STRLEN_P(cfg) + 1);
}
return true;
}

return false;
}

static bool ddtrace_conf_otel_resource_attributes_special(const char *tag, int len, zai_env_buffer buf, bool pre_rinit) {
static bool ddtrace_conf_otel_resource_attributes_special(const char *tag, int len, zai_env_buffer *buf, bool pre_rinit) {
if (!get_otel_value((zai_str)ZAI_STRL("OTEL_RESOURCE_ATTRIBUTES"), buf, pre_rinit)) {
return false;
}

for (char *cur = buf.ptr, *key_start = cur; *cur; ++cur) {
for (char *cur = buf->ptr, *key_start = cur; *cur; ++cur) {
if (*cur == '=') {
char *key_end = cur++;
while (*cur && *cur != ',') {
++cur;
}
if (key_end - key_start == len && memcmp(key_start, tag, len) == 0 && key_end[1]) {
size_t vallen = cur - (key_end + 1);
memcpy(buf.ptr, key_end + 1, vallen);
buf.ptr[vallen] = 0;
memcpy(buf->ptr, key_end + 1, vallen);
buf->ptr[vallen] = 0;
return true;
}
key_start = cur-- + 1;
Expand All @@ -78,92 +78,92 @@ static bool ddtrace_conf_otel_resource_attributes_special(const char *tag, int l
return false;
}

bool ddtrace_conf_otel_resource_attributes_env(zai_env_buffer buf, bool pre_rinit) {
bool ddtrace_conf_otel_resource_attributes_env(zai_env_buffer *buf, bool pre_rinit) {
return ddtrace_conf_otel_resource_attributes_special(ZEND_STRL("deployment.environment"), buf, pre_rinit);
}

bool ddtrace_conf_otel_resource_attributes_version(zai_env_buffer buf, bool pre_rinit) {
bool ddtrace_conf_otel_resource_attributes_version(zai_env_buffer *buf, bool pre_rinit) {
return ddtrace_conf_otel_resource_attributes_special(ZEND_STRL("service.version"), buf, pre_rinit);
}

bool ddtrace_conf_otel_service_name(zai_env_buffer buf, bool pre_rinit) {
bool ddtrace_conf_otel_service_name(zai_env_buffer *buf, bool pre_rinit) {
return get_otel_value((zai_str)ZAI_STRL("OTEL_SERVICE_NAME"), buf, pre_rinit)
|| ddtrace_conf_otel_resource_attributes_special(ZEND_STRL("service.name"), buf, pre_rinit);
}

bool ddtrace_conf_otel_log_level(zai_env_buffer buf, bool pre_rinit) {
bool ddtrace_conf_otel_log_level(zai_env_buffer *buf, bool pre_rinit) {
return get_otel_value((zai_str)ZAI_STRL("OTEL_LOG_LEVEL"), buf, pre_rinit);
}

bool ddtrace_conf_otel_propagators(zai_env_buffer buf, bool pre_rinit) {
bool ddtrace_conf_otel_propagators(zai_env_buffer *buf, bool pre_rinit) {
if (!get_otel_value((zai_str)ZAI_STRL("OTEL_PROPAGATORS"), buf, pre_rinit)) {
return false;
}
char *off = (char *)zend_memnstr(buf.ptr, ZEND_STRL("b3"), buf.ptr + strlen(buf.ptr));
if (off && (!off[strlen("b3")] || off[strlen("b3")] == ',') && strlen(buf.ptr) < buf.len - 100) {
memmove(off + strlen("b3 single header"), off + strlen("b3"), buf.ptr + strlen(buf.ptr) - (off + strlen("b3")) + 1);
char *off = (char *)zend_memnstr(buf->ptr, ZEND_STRL("b3"), buf->ptr + strlen(buf->ptr));
if (off && (!off[strlen("b3")] || off[strlen("b3")] == ',') && strlen(buf->ptr) < buf->len - 100) {
memmove(off + strlen("b3 single header"), off + strlen("b3"), buf->ptr + strlen(buf->ptr) - (off + strlen("b3")) + 1);
memcpy(off, "b3 single header", strlen("b3 single header"));
}
return true;
}

bool ddtrace_conf_otel_sample_rate(zai_env_buffer buf, bool pre_rinit) {
bool ddtrace_conf_otel_sample_rate(zai_env_buffer *buf, bool pre_rinit) {
if (!get_otel_value((zai_str)ZAI_STRL("OTEL_TRACES_SAMPLER"), buf, pre_rinit)) {
return false;
}

if (strcmp(buf.ptr, "always_on") == 0 || strcmp(buf.ptr, "parentbased_always_on") == 0) {
memcpy(buf.ptr, ZEND_STRS("1"));
if (strcmp(buf->ptr, "always_on") == 0 || strcmp(buf->ptr, "parentbased_always_on") == 0) {
memcpy(buf->ptr, ZEND_STRS("1"));
return true;
}
if (strcmp(buf.ptr, "always_off") == 0 || strcmp(buf.ptr, "parentbased_always_off") == 0) {
memcpy(buf.ptr, ZEND_STRS("0"));
if (strcmp(buf->ptr, "always_off") == 0 || strcmp(buf->ptr, "parentbased_always_off") == 0) {
memcpy(buf->ptr, ZEND_STRS("0"));
return true;
}
if (strcmp(buf.ptr, "traceidratio") == 0 || strcmp(buf.ptr, "parentbased_traceidratio") == 0) {
if (strcmp(buf->ptr, "traceidratio") == 0 || strcmp(buf->ptr, "parentbased_traceidratio") == 0) {
if (get_otel_value((zai_str)ZAI_STRL("OTEL_TRACES_SAMPLER_ARG"), buf, pre_rinit)) {
return true;
}
LOG_ONCE(WARN, "OTEL_TRACES_SAMPLER is %s, but is missing OTEL_TRACES_SAMPLER_ARG", buf.ptr);
LOG_ONCE(WARN, "OTEL_TRACES_SAMPLER is %s, but is missing OTEL_TRACES_SAMPLER_ARG", buf->ptr);
} else {
LOG_ONCE(WARN, "OTEL_TRACES_SAMPLER has invalid value: %s", buf.ptr);
LOG_ONCE(WARN, "OTEL_TRACES_SAMPLER has invalid value: %s", buf->ptr);
}
report_otel_cfg_telemetry_invalid("otel_traces_sampler", "dd_trace_sample_rate", pre_rinit);
return false;
}

bool ddtrace_conf_otel_traces_exporter(zai_env_buffer buf, bool pre_rinit) {
bool ddtrace_conf_otel_traces_exporter(zai_env_buffer *buf, bool pre_rinit) {
if (get_otel_value((zai_str)ZAI_STRL("OTEL_TRACES_EXPORTER"), buf, pre_rinit)) {
if (strcmp(buf.ptr, "none") == 0) {
memcpy(buf.ptr, ZEND_STRS("0"));
if (strcmp(buf->ptr, "none") == 0) {
memcpy(buf->ptr, ZEND_STRS("0"));
return true;
}
LOG_ONCE(WARN, "OTEL_TRACES_EXPORTER has invalid value: %s", buf.ptr);
LOG_ONCE(WARN, "OTEL_TRACES_EXPORTER has invalid value: %s", buf->ptr);
report_otel_cfg_telemetry_invalid("otel_traces_exporter", "dd_trace_enabled", pre_rinit);
}
return false;
}

bool ddtrace_conf_otel_metrics_exporter(zai_env_buffer buf, bool pre_rinit) {
bool ddtrace_conf_otel_metrics_exporter(zai_env_buffer *buf, bool pre_rinit) {
if (get_otel_value((zai_str)ZAI_STRL("OTEL_METRICS_EXPORTER"), buf, pre_rinit)) {
if (strcmp(buf.ptr, "none") == 0) {
memcpy(buf.ptr, ZEND_STRS("0"));
if (strcmp(buf->ptr, "none") == 0) {
memcpy(buf->ptr, ZEND_STRS("0"));
return true;
}
LOG_ONCE(WARN, "OTEL_METRICS_EXPORTER has invalid value: %s", buf.ptr);
LOG_ONCE(WARN, "OTEL_METRICS_EXPORTER has invalid value: %s", buf->ptr);
report_otel_cfg_telemetry_invalid("otel_metrics_exporter", "dd_integration_metrics_enabled", pre_rinit);
}
return false;
}

bool ddtrace_conf_otel_resource_attributes_tags(zai_env_buffer buf, bool pre_rinit) {
bool ddtrace_conf_otel_resource_attributes_tags(zai_env_buffer *buf, bool pre_rinit) {
if (!get_otel_value((zai_str)ZAI_STRL("OTEL_RESOURCE_ATTRIBUTES"), buf, pre_rinit)) {
return false;
}

char *out = buf.ptr;
char *out = buf->ptr;
int tags = 0;
for (char *cur = buf.ptr, *key_start = cur; *cur; ++cur) {
for (char *cur = buf->ptr, *key_start = cur; *cur; ++cur) {
if (*cur == '=') {
char *key = key_start, *key_end = cur++;
while (*cur && *cur != ',') {
Expand All @@ -190,7 +190,7 @@ bool ddtrace_conf_otel_resource_attributes_tags(zai_env_buffer buf, bool pre_rin
--cur;
}
}
if (out != buf.ptr) {
if (out != buf->ptr) {
--out;
}
*out = 0;
Expand Down
18 changes: 9 additions & 9 deletions ext/otel_config.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -3,14 +3,14 @@

#include <env/env.h>

bool ddtrace_conf_otel_resource_attributes_env(zai_env_buffer buf, bool pre_rinit);
bool ddtrace_conf_otel_resource_attributes_version(zai_env_buffer buf, bool pre_rinit);
bool ddtrace_conf_otel_service_name(zai_env_buffer buf, bool pre_rinit);
bool ddtrace_conf_otel_log_level(zai_env_buffer buf, bool pre_rinit);
bool ddtrace_conf_otel_propagators(zai_env_buffer buf, bool pre_rinit);
bool ddtrace_conf_otel_sample_rate(zai_env_buffer buf, bool pre_rinit);
bool ddtrace_conf_otel_traces_exporter(zai_env_buffer buf, bool pre_rinit);
bool ddtrace_conf_otel_metrics_exporter(zai_env_buffer buf, bool pre_rinit);
bool ddtrace_conf_otel_resource_attributes_tags(zai_env_buffer buf, bool pre_rinit);
bool ddtrace_conf_otel_resource_attributes_env(zai_env_buffer *buf, bool pre_rinit);
bool ddtrace_conf_otel_resource_attributes_version(zai_env_buffer *buf, bool pre_rinit);
bool ddtrace_conf_otel_service_name(zai_env_buffer *buf, bool pre_rinit);
bool ddtrace_conf_otel_log_level(zai_env_buffer *buf, bool pre_rinit);
bool ddtrace_conf_otel_propagators(zai_env_buffer *buf, bool pre_rinit);
bool ddtrace_conf_otel_sample_rate(zai_env_buffer *buf, bool pre_rinit);
bool ddtrace_conf_otel_traces_exporter(zai_env_buffer *buf, bool pre_rinit);
bool ddtrace_conf_otel_metrics_exporter(zai_env_buffer *buf, bool pre_rinit);
bool ddtrace_conf_otel_resource_attributes_tags(zai_env_buffer *buf, bool pre_rinit);

#endif // DD_OTEL_CONFIG_H
83 changes: 77 additions & 6 deletions zend_abstract_interface/config/config.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -12,11 +12,68 @@ HashTable zai_config_name_map = {0};
uint16_t zai_config_memoized_entries_count = 0;
zai_config_memoized_entry zai_config_memoized_entries[ZAI_CONFIG_ENTRIES_COUNT_MAX];

static bool zai_config_get_env_value(zai_str name, zai_env_buffer buf) {
/*
* File-local owning zai_option_str cache:
* - None (ptr == NULL): env var was unset.
* - Some with len == 0: env var was explicitly set to empty.
* - Some with len > 0: env var has a non-empty value.
*
* Each Some entry owns pemalloc(..., 1) memory and is freed in
* zai_config_clear_cached_env_values().
*/
static zai_option_str zai_config_cached_env_values[ZAI_CONFIG_ENTRIES_COUNT_MAX][ZAI_CONFIG_NAMES_COUNT_MAX];

bool zai_config_get_cached_env_value(zai_config_id id, uint8_t name_index, zai_env_buffer *buf) {
ZEND_ASSERT(buf != NULL);
ZEND_ASSERT(buf->ptr != NULL);
ZEND_ASSERT(buf->len > 0);
ZEND_ASSERT(id < zai_config_memoized_entries_count);
ZEND_ASSERT(name_index < zai_config_memoized_entries[id].names_count);
zai_option_str cached = zai_config_cached_env_values[id][name_index];
if (zai_option_str_is_some(cached)) {
buf->ptr = (char *)cached.ptr;
buf->len = cached.len;
return true;
}
return false;
}

static void zai_config_cache_env_values(void) {
for (zai_config_id i = 0; i < zai_config_memoized_entries_count; i++) {
zai_config_memoized_entry *memoized = &zai_config_memoized_entries[i];
for (uint8_t n = 0; n < memoized->names_count; n++) {
zai_str name = {.len = memoized->names[n].len, .ptr = memoized->names[n].ptr};
char *value = getenv(name.ptr);
if (!value) {
continue;
}
size_t len = strlen(value);
char *copy = pemalloc(len + 1, 1);
memcpy(copy, value, len + 1);
zai_config_cached_env_values[i][n] = zai_option_str_from_raw_parts(copy, len);
}
}
}

static void zai_config_clear_cached_env_values(void) {
for (zai_config_id i = 0; i < zai_config_memoized_entries_count; i++) {
zai_config_memoized_entry *memoized = &zai_config_memoized_entries[i];
for (uint8_t n = 0; n < memoized->names_count; n++) {
zai_option_str *cached = &zai_config_cached_env_values[i][n];
if (zai_option_str_is_some(*cached)) {
pefree((char *)cached->ptr, 1);
}
*cached = ZAI_OPTION_STR_NONE;
}
}
}

static bool zai_config_get_env_value(zai_str name, zai_config_id id, uint8_t name_index, zai_env_buffer *buf) {
// TODO Handle other return codes
// We want to explicitly allow pre-RINIT access to env vars here. So that callers can have an early view at config.
// But in general allmost all configurations shall only be accessed after first RINIT. (the trivial getter will
return zai_getenv_ex(name, buf, true) == ZAI_ENV_SUCCESS;
if (zai_getenv(name, buf) == ZAI_ENV_SUCCESS) {
return true;
}
return zai_config_get_cached_env_value(id, name_index, buf);
}

static inline void zai_config_process_env(zai_config_memoized_entry *memoized, zai_env_buffer buf, zai_option_str *value) {
Expand All @@ -40,6 +97,8 @@ static void zai_config_find_and_set_value(zai_config_memoized_entry *memoized, z

int16_t name_index = 0;
for (; name_index < memoized->names_count; name_index++) {
buf.ptr = buf_storage;
buf.len = sizeof(buf_storage);
zai_str name = {.len = memoized->names[name_index].len, .ptr = memoized->names[name_index].ptr};
zai_config_stable_file_entry *entry = zai_config_stable_file_get_value(name);
if (entry && entry->source == DDOG_LIBRARY_CONFIG_SOURCE_FLEET_STABLE_CONFIG) {
Expand All @@ -48,7 +107,7 @@ static void zai_config_find_and_set_value(zai_config_memoized_entry *memoized, z
name_index = ZAI_CONFIG_ORIGIN_FLEET_STABLE;
memoized->config_id = (zai_str) ZAI_STR_FROM_ZSTR(entry->config_id);
break;
} else if (zai_config_get_env_value(name, buf)) {
} else if (zai_config_get_env_value(name, id, (uint8_t)name_index, &buf)) {
zai_config_process_env(memoized, buf, &value);
break;
} else if (entry && entry->source == DDOG_LIBRARY_CONFIG_SOURCE_LOCAL_STABLE_CONFIG) {
Expand All @@ -59,7 +118,10 @@ static void zai_config_find_and_set_value(zai_config_memoized_entry *memoized, z
break;
}
}
if (!value.len && memoized->env_config_fallback && memoized->env_config_fallback(buf, true)) {

buf.ptr = buf_storage;
buf.len = sizeof(buf_storage);
if (!value.len && memoized->env_config_fallback && memoized->env_config_fallback(&buf, true)) {
zai_config_process_env(memoized, buf, &value);
name_index = ZAI_CONFIG_ORIGIN_MODIFIED;
}
Expand Down Expand Up @@ -148,6 +210,7 @@ bool zai_config_minit(zai_config_entry entries[], size_t entries_count, zai_conf
if (!entries || !entries_count) return false;
if (!zai_json_setup_bindings()) return false;
zai_config_entries_init(entries, entries_count);
zai_config_cache_env_values();
zai_config_ini_minit(env_to_ini, module_number);
zai_config_stable_file_minit();
#if PHP_VERSION_ID >= 70300 && PHP_VERSION_ID < 70400
Expand All @@ -164,6 +227,7 @@ static void zai_config_dtor_memoized_zvals(void) {

void zai_config_mshutdown(void) {
zai_config_dtor_memoized_zvals();
zai_config_clear_cached_env_values();
if (zai_config_name_map.nTableSize) {
zend_hash_destroy(&zai_config_name_map);
}
Expand Down Expand Up @@ -237,6 +301,13 @@ void zai_config_first_time_rinit(bool in_request) {
(void)in_request;
#endif

if (in_request) {
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@bwoebi bwoebi Feb 27, 2026

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We only need it for FPM, right? So let's add a sapi_module check here?
Saving some minor time on CLI scripts.

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@morrisonlevi morrisonlevi Feb 27, 2026 •
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I'm not sure what litespeed does, and IIRC we did have a customer using it. How about a not-CLI SAPI check instead? That way web SAPIs stay consistent, but it's skipped on CLI where it's unnecessary.

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@morrisonlevi morrisonlevi Feb 27, 2026

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I think it's reasonably clearer now. Patch is smaller, at least xD

// Refresh process env snapshot for SAPIs like FPM that materialize
// pool env values just before the first request.
zai_config_clear_cached_env_values();
zai_config_cache_env_values();
}

for (uint16_t i = 0; i < zai_config_memoized_entries_count; i++) {
zai_config_memoized_entry *memoized = &zai_config_memoized_entries[i];
zai_config_find_and_set_value(memoized, i);
Expand Down
2 changes: 2 additions & 0 deletions zend_abstract_interface/config/config.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -6,6 +6,7 @@
#include <stddef.h>
#include <stdint.h>

#include "../env/env.h"
#include "../zai_string/string.h"
#include "config_decode.h"

Expand Down Expand Up @@ -114,5 +115,6 @@ bool zai_config_get_id_by_name(zai_str name, zai_config_id *id);
void zai_config_register_config_id(zai_config_name *name, zai_config_id id);

bool zai_config_is_initialized(void);
bool zai_config_get_cached_env_value(zai_config_id id, uint8_t name_index, zai_env_buffer *buf);

#endif // ZAI_CONFIG_H
9 changes: 7 additions & 2 deletions zend_abstract_interface/config/config_ini.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -438,6 +438,8 @@ void zai_config_ini_rinit(void) {
// makes only sense to update INIs once, avoid rereading env unnecessarily
if (!env_to_ini_name || !memoized->original_on_modify) {
for (uint8_t name_index = 0; name_index < memoized->names_count; name_index++) {
buf.ptr = buf_storage;
buf.len = sizeof(buf_storage);
zai_str name = ZAI_STR_NEW(memoized->names[name_index].ptr, memoized->names[name_index].len);
zai_config_stable_file_entry *entry = zai_config_stable_file_get_value(name);
if (entry && entry->source == DDOG_LIBRARY_CONFIG_SOURCE_FLEET_STABLE_CONFIG
Expand All @@ -446,7 +448,8 @@ void zai_config_ini_rinit(void) {
memoized->name_index = ZAI_CONFIG_ORIGIN_FLEET_STABLE;
memoized->config_id = (zai_str) ZAI_STR_FROM_ZSTR(entry->config_id);
goto next_entry;
} else if (zai_getenv_ex(name, buf, false) == ZAI_ENV_SUCCESS
} else if ((zai_getenv(name, &buf) == ZAI_ENV_SUCCESS
|| zai_config_get_cached_env_value(i, name_index, &buf))
&& zai_config_process_runtime_env(memoized, buf, in_startup, i, name_index)) {
goto next_entry;
} else if (entry && entry->source == DDOG_LIBRARY_CONFIG_SOURCE_LOCAL_STABLE_CONFIG
Expand All @@ -458,7 +461,9 @@ void zai_config_ini_rinit(void) {
}
}

if (memoized->env_config_fallback && memoized->env_config_fallback(buf, false) && zai_config_process_runtime_env(memoized, buf, in_startup, i, 0)) {
buf.ptr = buf_storage;
buf.len = sizeof(buf_storage);
if (memoized->env_config_fallback && memoized->env_config_fallback(&buf, false) && zai_config_process_runtime_env(memoized, buf, in_startup, i, 0)) {
goto next_entry;
}
}
Expand Down
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