opentelemetry: add OTLP JSON and OTLP Proto helpers

CMakeLists.txt

@@ -723,15 +723,20 @@ endif()
 # ring buffer library
 add_subdirectory(${FLB_PATH_LIB_RING_BUFFER} EXCLUDE_FROM_ALL)
 
-# yyson
-add_subdirectory(${FLB_PATH_LIB_YYJSON} EXCLUDE_FROM_ALL)
-if (TARGET yyjson AND NOT FLB_COVERAGE AND
-    CMAKE_C_COMPILER_ID MATCHES "GNU|Clang|AppleClang|Intel")
-  # yyjson's O0 reader can exceed the default coroutine stack budget.
-  # Keep debug symbols, but force enough optimization to shrink the frame.
-  target_compile_options(yyjson PRIVATE
-    $<$<AND:$<COMPILE_LANGUAGE:C>,$<OR:$<CONFIG:Debug>,$<CONFIG:RelWithDebInfo>>>:-Og>
-  )
+# yyjson
+option(FLB_YYJSON "Enable yyjson backend" ON)
+if(FLB_YYJSON)
+  add_subdirectory(${FLB_PATH_LIB_YYJSON} EXCLUDE_FROM_ALL)
+  FLB_DEFINITION(FLB_HAVE_YYJSON)
+
+  if (TARGET yyjson AND NOT FLB_COVERAGE AND
+      CMAKE_C_COMPILER_ID MATCHES "GNU|Clang|AppleClang|Intel")
+    # yyjson's O0 reader can exceed the default coroutine stack budget.
+    # Keep debug symbols, but force enough optimization to shrink the frame.
+    target_compile_options(yyjson PRIVATE
+      $<$<AND:$<COMPILE_LANGUAGE:C>,$<OR:$<CONFIG:Debug>,$<CONFIG:RelWithDebInfo>>>:-Og>
+    )
+  endif()
 endif()
 
 # Avro

cmake/headers.cmake

@@ -35,7 +35,6 @@ include_directories(
   ${FLB_PATH_ROOT_SOURCE}/${FLB_PATH_LIB_CTRACES}/include
   ${FLB_PATH_ROOT_SOURCE}/${FLB_PATH_LIB_CPROFILES}/include
   ${FLB_PATH_ROOT_SOURCE}/${FLB_PATH_LIB_RING_BUFFER}/lwrb/src/include
-  ${FLB_PATH_ROOT_SOURCE}/${FLB_PATH_LIB_YYJSON}/src
   ${FLB_PATH_ROOT_BINARY_DIR}/${FLB_PATH_LIB_JANSSON}/include
   ${FLB_PATH_ROOT_BINARY_DIR}/lib/cmetrics
   ${FLB_PATH_ROOT_BINARY_DIR}/lib/cprofiles/include
@@ -45,6 +44,10 @@ include_directories(
   ${FLB_PATH_ROOT_BINARY_DIR}/lib/monkey/include/monkey/
   )
 
+if(FLB_YYJSON)
+  include_directories(${FLB_PATH_ROOT_SOURCE}/${FLB_PATH_LIB_YYJSON}/src)
+endif()
+
 if(FLB_UTF8_ENCODER)
   include_directories(${FLB_PATH_ROOT_SOURCE}/${FLB_PATH_LIB_TUTF8E}/include)
 endif()

include/fluent-bit/flb_input.h

@@ -446,6 +446,7 @@ struct flb_input_instance {
     struct flb_hash_table *ht_metric_chunks;
     struct flb_hash_table *ht_trace_chunks;
     struct flb_hash_table *ht_profile_chunks;
+    pthread_mutex_t metrics_chunk_lock;
 
     /* TLS settings */
     int use_tls;                         /* bool, try to use TLS for I/O */

include/fluent-bit/flb_json.h

@@ -0,0 +1,106 @@
+/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+
+/*  Fluent Bit
+ *  ==========
+ *  Copyright (C) 2015-2026 The Fluent Bit Authors
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+#ifndef FLB_JSON_H
+#define FLB_JSON_H
+
+#include <stddef.h>
+
+struct flb_json_doc;
+struct flb_json_val;
+struct flb_json_mut_doc;
+struct flb_json_mut_val;
+
+struct flb_json_doc *flb_json_read(const char *input, size_t length);
+void flb_json_doc_destroy(struct flb_json_doc *document);
+struct flb_json_val *flb_json_doc_get_root(struct flb_json_doc *document);
+char *flb_json_write(struct flb_json_doc *document, size_t *length);
+char *flb_json_write_pretty(struct flb_json_doc *document, size_t *length);
+char *flb_json_prettify(const char *input, size_t input_length, size_t *length);
+struct flb_json_val *flb_json_obj_get(struct flb_json_val *value,
+                                      const char *key);
+size_t flb_json_arr_size(struct flb_json_val *value);
+struct flb_json_val *flb_json_arr_get(struct flb_json_val *value, size_t index);
+
+struct flb_json_mut_doc *flb_json_mut_doc_create(void);
+void flb_json_mut_doc_destroy(struct flb_json_mut_doc *document);
+void flb_json_mut_doc_set_root(struct flb_json_mut_doc *document,
+                               struct flb_json_mut_val *root);
+char *flb_json_mut_write(struct flb_json_mut_doc *document, size_t *length);
+char *flb_json_mut_write_pretty(struct flb_json_mut_doc *document, size_t *length);
+
+struct flb_json_mut_val *flb_json_mut_obj(struct flb_json_mut_doc *document);
+struct flb_json_mut_val *flb_json_mut_arr(struct flb_json_mut_doc *document);
+struct flb_json_mut_val *flb_json_mut_strncpy(struct flb_json_mut_doc *document,
+                                              const char *value,
+                                              size_t length);
+struct flb_json_mut_val *flb_json_val_mut_copy(struct flb_json_mut_doc *target,
+                                               struct flb_json_val *source);
+
+int flb_json_mut_arr_add_real(struct flb_json_mut_doc *document,
+                              struct flb_json_mut_val *array,
+                              double value);
+int flb_json_mut_arr_add_strncpy(struct flb_json_mut_doc *document,
+                                 struct flb_json_mut_val *array,
+                                 const char *value,
+                                 size_t length);
+int flb_json_mut_arr_add_val(struct flb_json_mut_val *array,
+                             struct flb_json_mut_val *value);
+size_t flb_json_mut_arr_size(struct flb_json_mut_val *array);
+
+int flb_json_mut_obj_add_bool(struct flb_json_mut_doc *document,
+                              struct flb_json_mut_val *object,
+                              const char *key,
+                              int value);
+int flb_json_mut_obj_add_int(struct flb_json_mut_doc *document,
+                             struct flb_json_mut_val *object,
+                             const char *key,
+                             long long value);
+int flb_json_mut_obj_add_real(struct flb_json_mut_doc *document,
+                              struct flb_json_mut_val *object,
+                              const char *key,
+                              double value);
+int flb_json_mut_obj_add_str(struct flb_json_mut_doc *document,
+                             struct flb_json_mut_val *object,
+                             const char *key,
+                             const char *value);
+int flb_json_mut_obj_add_strcpy(struct flb_json_mut_doc *document,
+                                struct flb_json_mut_val *object,
+                                const char *key,
+                                const char *value);
+int flb_json_mut_obj_add_strn(struct flb_json_mut_doc *document,
+                              struct flb_json_mut_val *object,
+                              const char *key,
+                              const char *value,
+                              size_t length);
+int flb_json_mut_obj_add_strncpy(struct flb_json_mut_doc *document,
+                                 struct flb_json_mut_val *object,
+                                 const char *key,
+                                 const char *value,
+                                 size_t length);
+int flb_json_mut_obj_add_uint(struct flb_json_mut_doc *document,
+                              struct flb_json_mut_val *object,
+                              const char *key,
+                              unsigned long long value);
+int flb_json_mut_obj_add_val(struct flb_json_mut_doc *document,
+                             struct flb_json_mut_val *object,
+                             const char *key,
+                             struct flb_json_mut_val *value);
+
+#endif

include/fluent-bit/flb_opentelemetry.h

@@ -21,6 +21,7 @@
 #define FLB_OPENTELEMETRY_H
 
 #include <fluent-bit/flb_log_event_encoder.h>
+#include <fluent-bit/flb_sds.h>
 #include <cfl/cfl.h>
 #include <msgpack.h>
 #include <stdint.h>
@@ -92,6 +93,32 @@ struct flb_otel_error_map {
     int code;
 };
 
+struct cmt;
+struct ctrace;
+struct flb_log_event;
+
+enum flb_opentelemetry_otlp_json_result {
+    FLB_OPENTELEMETRY_OTLP_JSON_SUCCESS = 0,
+    FLB_OPENTELEMETRY_OTLP_JSON_INVALID_ARGUMENT = -1,
+    FLB_OPENTELEMETRY_OTLP_JSON_NOT_SUPPORTED = -2,
+    FLB_OPENTELEMETRY_OTLP_JSON_INVALID_LOG_EVENT = -3
+};
+
+enum flb_opentelemetry_otlp_proto_result {
+    FLB_OPENTELEMETRY_OTLP_PROTO_SUCCESS = 0,
+    FLB_OPENTELEMETRY_OTLP_PROTO_INVALID_ARGUMENT = -1,
+    FLB_OPENTELEMETRY_OTLP_PROTO_NOT_SUPPORTED = -2,
+    FLB_OPENTELEMETRY_OTLP_PROTO_INVALID_LOG_EVENT = -3
+};
+
+struct flb_opentelemetry_otlp_json_options {
+    int logs_require_otel_metadata;
+    const char *logs_body_key;
+    const char **logs_body_keys;
+    size_t logs_body_key_count;
+    int logs_body_key_attributes;
+};
+
 static struct flb_otel_error_map otel_error_map[] = {
     {"FLB_OTEL_RESOURCE_INVALID_ATTRIBUTE",                  FLB_OTEL_RESOURCE_INVALID_ATTRIBUTE},
     {"FLB_OTEL_LOGS_ERR_UNEXPECTED_ROOT_OBJECT_TYPE",        FLB_OTEL_LOGS_ERR_UNEXPECTED_ROOT_OBJECT_TYPE},
@@ -180,6 +207,50 @@ int flb_opentelemetry_metrics_json_to_cmt(struct cfl_list *context_list,
 struct ctrace *flb_opentelemetry_json_traces_to_ctrace(const char *body, size_t len,
                                                        int *error_status);
 
+/*
+ * OTLP JSON encoding entry points shared by outputs and processors.
+ * Traces and metrics are intentionally typed to keep transport plugins
+ * independent from OpenTelemetry schema details.
+ */
+flb_sds_t flb_opentelemetry_traces_to_otlp_json(struct ctrace *context,
+                                                int *result);
+
+flb_sds_t flb_opentelemetry_traces_msgpack_to_otlp_json(const void *data,
+                                                        size_t size,
+                                                        int *result);
+
+flb_sds_t flb_opentelemetry_metrics_to_otlp_json(struct cmt *context,
+                                                 int *result);
+
+flb_sds_t flb_opentelemetry_metrics_msgpack_to_otlp_json(const void *data,
+                                                         size_t size,
+                                                         int *result);
+
+flb_sds_t flb_opentelemetry_logs_to_otlp_json(const void *event_chunk_data,
+                                              size_t event_chunk_size,
+                                              struct flb_opentelemetry_otlp_json_options *options,
+                                              int *result);
+
+flb_sds_t flb_opentelemetry_traces_to_otlp_proto(struct ctrace *context,
+                                                 int *result);
+
+flb_sds_t flb_opentelemetry_metrics_to_otlp_proto(struct cmt *context,
+                                                  int *result);
+
+flb_sds_t flb_opentelemetry_metrics_msgpack_to_otlp_proto(const void *data,
+                                                          size_t size,
+                                                          int *result);
+
+flb_sds_t flb_opentelemetry_logs_to_otlp_proto(const void *event_chunk_data,
+                                               size_t event_chunk_size,
+                                               struct flb_opentelemetry_otlp_json_options *options,
+                                               int *result);
+
+int flb_opentelemetry_log_is_otlp(struct flb_log_event *log_event);
+
+int flb_opentelemetry_logs_chunk_is_otlp(const void *event_chunk_data,
+                                         size_t event_chunk_size);
+
 /* OpenTelemetry utils */
 int flb_otel_utils_find_map_entry_by_key(msgpack_object_map *map,
                                          char *key,

include/fluent-bit/flb_pack.h

@@ -27,8 +27,6 @@
 #include <fluent-bit/flb_config.h>
 
 #include <msgpack.h>
-#include <yyjson.h>
-
 /* JSON types */
 #define FLB_PACK_JSON_UNDEFINED     JSMN_UNDEFINED
 #define FLB_PACK_JSON_OBJECT        JSMN_OBJECT
@@ -60,6 +58,8 @@
 #define FLB_PACK_JSON_FORMAT_JSON        1
 #define FLB_PACK_JSON_FORMAT_STREAM      2
 #define FLB_PACK_JSON_FORMAT_LINES       3
+#define FLB_PACK_JSON_FORMAT_OTLP        4
+#define FLB_PACK_JSON_FORMAT_OTLP_PRETTY 5
 
 struct flb_pack_state {
     int multiple;         /* support multiple jsons? */
@@ -81,11 +81,13 @@ int flb_pack_json(const char *js, size_t len, char **buffer, size_t *size,
                   int *root_type, size_t *consumed);
 int flb_pack_json_recs(const char *js, size_t len, char **buffer, size_t *size,
                        int *root_type, int *out_records, size_t *consumed);
+#ifdef FLB_HAVE_YYJSON
 int flb_pack_json_yyjson(const char *js, size_t len, char **buffer, size_t *size,
                          int *root_type, size_t *consumed);
 int flb_pack_json_recs_yyjson(const char *js, size_t len, char **buffer,
                               size_t *size, int *root_type, int *out_records,
                               size_t *consumed);
+#endif
 
 int flb_pack_state_init(struct flb_pack_state *s);
 void flb_pack_state_reset(struct flb_pack_state *s);

include/fluent-bit/flb_time.h

@@ -87,7 +87,7 @@ static inline void flb_time_copy(struct flb_time *dst, struct flb_time *src)
 static inline void flb_time_from_uint64(struct flb_time *dst, uint64_t value)
 {
     dst->tm.tv_sec = (long) (value / 1000000000L);
-    dst->tm.tv_nsec = (long) (value - dst->tm.tv_sec);
+    dst->tm.tv_nsec = (long) (value - ((uint64_t) dst->tm.tv_sec * 1000000000L));
 }
 
 static inline void flb_time_from_double(struct flb_time *dst, double d)

lib/cmetrics/CMakeLists.txt

@@ -5,8 +5,8 @@ set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
 
 # CMetrics Version
 set(CMT_VERSION_MAJOR  2)
-set(CMT_VERSION_MINOR  0)
-set(CMT_VERSION_PATCH  5)
+set(CMT_VERSION_MINOR  1)
+set(CMT_VERSION_PATCH  1)
 set(CMT_VERSION_STR "${CMT_VERSION_MAJOR}.${CMT_VERSION_MINOR}.${CMT_VERSION_PATCH}")
 
 # Include helpers