Merging upstream version 1.44.3.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

3 files changed, 805 insertions, 0 deletions

diff --git a/fluent-bit/plugins/in_cpu/CMakeLists.txt b/fluent-bit/plugins/in_cpu/CMakeLists.txt
new file mode 100644
index 00000000..4ed82c5d
--- /dev/null
+++ b/fluent-bit/plugins/in_cpu/CMakeLists.txt
@@ -0,0 +1,4 @@
+set(src
+  cpu.c)
+
+FLB_PLUGIN(in_cpu "${src}" "")
diff --git a/fluent-bit/plugins/in_cpu/cpu.c b/fluent-bit/plugins/in_cpu/cpu.c
new file mode 100644
index 00000000..5d049eb9
--- /dev/null
+++ b/fluent-bit/plugins/in_cpu/cpu.c
@@ -0,0 +1,672 @@
+/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+
+/*  Fluent Bit
+ *  ==========
+ *  Copyright (C) 2015-2022 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.
+ */
+
+#include <fluent-bit/flb_info.h>
+#include <fluent-bit/flb_input.h>
+#include <fluent-bit/flb_input_plugin.h>
+#include <fluent-bit/flb_config.h>
+#include <fluent-bit/flb_pack.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <math.h>
+
+#include "cpu.h"
+
+static inline void snapshot_key_format(int cpus, struct cpu_snapshot *snap_arr)
+{
+    int i;
+    struct cpu_snapshot *snap;
+
+    snap = &snap_arr[0];
+    memcpy(snap->k_cpu.name, "cpu", 3);
+    snap->k_cpu.name[3] = '\0';
+
+    for (i = 1; i <= cpus; i++) {
+        snap = (struct cpu_snapshot *) &snap_arr[i];
+        CPU_KEY_FORMAT(snap, cpu, i);
+        CPU_KEY_FORMAT(snap, user, i);
+        CPU_KEY_FORMAT(snap, system, i);
+    }
+}
+
+static int snapshots_init(int cpus, struct cpu_stats *cstats)
+{
+    cstats->snap_a = flb_calloc(1, sizeof(struct cpu_snapshot) * (cpus + 1));
+    if (!cstats->snap_a) {
+        flb_errno();
+        return -1;
+    }
+
+    cstats->snap_b = flb_malloc(sizeof(struct cpu_snapshot) * (cpus + 1));
+    if (!cstats->snap_b) {
+        flb_errno();
+        return -1;
+    }
+
+    /* Initialize each array */
+    snapshot_key_format(cpus, cstats->snap_a);
+    snapshot_key_format(cpus, cstats->snap_b);
+    cstats->snap_active = CPU_SNAP_ACTIVE_A;
+    return 0;
+}
+
+static inline void snapshots_switch(struct cpu_stats *cstats)
+{
+    if (cstats->snap_active == CPU_SNAP_ACTIVE_A) {
+        cstats->snap_active = CPU_SNAP_ACTIVE_B;
+    }
+    else {
+        cstats->snap_active = CPU_SNAP_ACTIVE_A;
+    }
+}
+
+/* Retrieve CPU load from the system (through ProcFS) */
+static inline double proc_cpu_load(int cpus, struct cpu_stats *cstats)
+{
+    int i;
+    int ret;
+    char line[255];
+    size_t len = 0;
+    char *fmt;
+    FILE *f;
+    struct cpu_snapshot *s;
+    struct cpu_snapshot *snap_arr;
+
+    f = fopen("/proc/stat", "r");
+    if (f == NULL) {
+        flb_errno();
+        return -1;
+    }
+
+    if (cstats->snap_active == CPU_SNAP_ACTIVE_A) {
+        snap_arr = cstats->snap_a;
+    }
+    else {
+        snap_arr = cstats->snap_b;
+    }
+
+    /* Always read (n_cpus + 1) lines */
+    for (i = 0; i <= cpus; i++) {
+        if (fgets(line, sizeof(line) - 1, f)) {
+            len = strlen(line);
+            if (line[len - 1] == '\n') {
+                line[--len] = 0;
+                if (len && line[len - 1] == '\r') {
+                    line[--len] = 0;
+                }
+            }
+
+            s = &snap_arr[i];
+            if (i == 0) {
+                fmt = " cpu  %lu %lu %lu %lu %lu";
+                ret = sscanf(line,
+                             fmt,
+                             &s->v_user,
+                             &s->v_nice,
+                             &s->v_system,
+                             &s->v_idle,
+                             &s->v_iowait);
+                if (ret < 5) {
+                    fclose(f);
+                    return -1;
+                }
+            }
+            else {
+                fmt = " %s %lu %lu %lu %lu %lu";
+                ret = sscanf(line,
+                             fmt,
+                             s->v_cpuid,
+                             &s->v_user,
+                             &s->v_nice,
+                             &s->v_system,
+                             &s->v_idle,
+                             &s->v_iowait);
+                if (ret <= 5) {
+                    fclose(f);
+                    return -1;
+                }
+            }
+        }
+        else {
+            break;
+        }
+    }
+
+    fclose(f);
+    return 0;
+}
+
+/* Retrieve CPU stats for a given PID */
+static inline double proc_cpu_pid_load(struct flb_cpu *ctx,
+                                       pid_t pid, struct cpu_stats *cstats)
+{
+    int ret;
+    char *p;
+    char line[255];
+    char *fmt = ") %c %d %d %d %d %d %u %lu %lu %lu %lu %lu %lu ";
+    FILE *f;
+    /* sscanf variables (ss_N) to perform scanning */
+    unsigned char ss_state;
+    unsigned int ss_ppid;
+    unsigned int ss_pgrp;
+    unsigned int ss_session;
+    unsigned int ss_tty_nr;
+    unsigned int ss_tpgid;
+    unsigned int ss_flags;
+    unsigned long ss_minflt;
+    unsigned long ss_cmdinflt;
+    unsigned long ss_majflt;
+    unsigned long ss_cmajflt;
+    struct cpu_snapshot *s;
+
+    /* Read the process stats */
+    snprintf(line, sizeof(line) - 1, "/proc/%d/stat", pid);
+    f = fopen(line, "r");
+    if (f == NULL) {
+        flb_errno();
+        flb_plg_error(ctx->ins, "error opening stats file %s", line);
+        return -1;
+    }
+
+    if (cstats->snap_active == CPU_SNAP_ACTIVE_A) {
+        s = cstats->snap_a;
+    }
+    else {
+        s = cstats->snap_b;
+    }
+
+    if (fgets(line, sizeof(line) - 1, f) == NULL) {
+        flb_plg_error(ctx->ins, "cannot read process %ld stats", (long) pid);
+        fclose(f);
+        return -1;
+    }
+
+    errno = 0;
+
+    /* skip first two values (after process name) */
+    p = line;
+    while (*p != ')') p++;
+
+    errno = 0;
+    ret = sscanf(p,
+                 fmt,
+                 &ss_state,
+                 &ss_ppid,
+                 &ss_pgrp,
+                 &ss_session,
+                 &ss_tty_nr,
+                 &ss_tpgid,
+                 &ss_flags,
+                 &ss_minflt,
+                 &ss_cmdinflt,
+                 &ss_majflt,
+                 &ss_cmajflt,
+                 &s->v_user,
+                 &s->v_system);
+    if (errno != 0) {
+        flb_errno();
+        flb_plg_error(ctx->ins, "pid sscanf failed ret=%i", ret);
+    }
+
+    fclose(f);
+    return 0;
+}
+
+/*
+ * Given the two snapshots, calculate the % used in user and kernel space,
+ * it returns the active snapshot.
+ */
+struct cpu_snapshot *snapshot_percent(struct cpu_stats *cstats,
+                                      struct flb_cpu *ctx)
+{
+    int i;
+    unsigned long sum_pre;
+    unsigned long sum_now;
+    struct cpu_snapshot *arr_pre = cstats->snap_b;
+    struct cpu_snapshot *arr_now = cstats->snap_a;
+    struct cpu_snapshot *snap_pre = NULL;
+    struct cpu_snapshot *snap_now = NULL;
+
+    if (cstats->snap_active == CPU_SNAP_ACTIVE_A) {
+        arr_now = cstats->snap_a;
+        arr_pre = cstats->snap_b;
+    }
+    else if (cstats->snap_active == CPU_SNAP_ACTIVE_B) {
+        arr_now = cstats->snap_b;
+        arr_pre = cstats->snap_a;
+    }
+
+    for (i = 0; i <= ctx->n_processors; i++) {
+        snap_pre = &arr_pre[i];
+        snap_now = &arr_now[i];
+
+        /* Calculate overall CPU usage (user space + kernel space */
+        sum_pre = (snap_pre->v_user + snap_pre->v_nice + snap_pre->v_system);
+        sum_now = (snap_now->v_user + snap_now->v_nice + snap_now->v_system);
+
+        if (i == 0) {
+            snap_now->p_cpu = CPU_METRIC_SYS_AVERAGE(sum_pre, sum_now, ctx);
+        }
+        else {
+            snap_now->p_cpu = CPU_METRIC_USAGE(sum_pre, sum_now, ctx);
+        }
+
+        /* User space CPU% */
+        sum_pre = (snap_pre->v_user + snap_pre->v_nice);
+        sum_now = (snap_now->v_user + snap_now->v_nice);
+        if (i == 0) {
+            snap_now->p_user = CPU_METRIC_SYS_AVERAGE(sum_pre, sum_now, ctx);
+        }
+        else {
+            snap_now->p_user = CPU_METRIC_USAGE(sum_pre, sum_now, ctx);
+        }
+
+        /* Kernel space CPU% */
+        if (i == 0) {
+            snap_now->p_system = CPU_METRIC_SYS_AVERAGE(snap_pre->v_system,
+                                                        snap_now->v_system,
+                                                        ctx);
+        }
+        else {
+            snap_now->p_system = CPU_METRIC_USAGE(snap_pre->v_system,
+                                                  snap_now->v_system,
+                                                  ctx);
+        }
+
+#ifdef FLB_TRACE
+        if (i == 0) {
+            flb_trace("cpu[all] all=%s%f%s user=%s%f%s system=%s%f%s",
+                      ANSI_BOLD, snap_now->p_cpu, ANSI_RESET,
+                      ANSI_BOLD, snap_now->p_user, ANSI_RESET,
+                      ANSI_BOLD, snap_now->p_system, ANSI_RESET);
+        }
+        else {
+            flb_trace("cpu[i=%i] all=%f user=%f system=%f",
+                      i-1, snap_now->p_cpu,
+                      snap_now->p_user, snap_now->p_system);
+        }
+#endif
+    }
+
+    return arr_now;
+}
+
+struct cpu_snapshot *snapshot_pid_percent(struct cpu_stats *cstats,
+                                          struct flb_cpu *ctx)
+{
+    unsigned long sum_pre;
+    unsigned long sum_now;
+    struct cpu_snapshot *snap_pre = NULL;
+    struct cpu_snapshot *snap_now = NULL;
+
+    if (cstats->snap_active == CPU_SNAP_ACTIVE_A) {
+        snap_now = cstats->snap_a;
+        snap_pre = cstats->snap_b;
+    }
+    else if (cstats->snap_active == CPU_SNAP_ACTIVE_B) {
+        snap_now = cstats->snap_b;
+        snap_pre = cstats->snap_a;
+    }
+
+    /* Calculate overall CPU usage (user space + kernel space */
+    sum_pre = (snap_pre->v_user + snap_pre->v_system);
+    sum_now = (snap_now->v_user + snap_now->v_system);
+
+    snap_now->p_cpu = CPU_METRIC_SYS_AVERAGE(sum_pre, sum_now, ctx);
+
+    /* User space CPU% */
+    snap_now->p_user = CPU_METRIC_SYS_AVERAGE(snap_pre->v_user,
+                                              snap_now->v_user,
+                                              ctx);
+
+    /* Kernel space CPU% */
+    snap_now->p_system = CPU_METRIC_SYS_AVERAGE(snap_pre->v_system,
+                                                snap_now->v_system,
+                                                ctx);
+
+#ifdef FLB_TRACE
+    flb_trace("cpu[pid=%i] all=%s%f%s user=%s%f%s system=%s%f%s",
+              ctx->pid,
+              ANSI_BOLD, snap_now->p_cpu, ANSI_RESET,
+              ANSI_BOLD, snap_now->p_user, ANSI_RESET,
+              ANSI_BOLD, snap_now->p_system, ANSI_RESET);
+#endif
+
+    return snap_now;
+}
+
+static int cpu_collect_system(struct flb_input_instance *ins,
+                              struct flb_config *config, void *in_context)
+{
+    int i;
+    int ret;
+    struct flb_cpu *ctx = in_context;
+    struct cpu_stats *cstats = &ctx->cstats;
+    struct cpu_snapshot *s;
+
+    (void) config;
+
+    /* Get overall system CPU usage */
+    ret = proc_cpu_load(ctx->n_processors, cstats);
+    if (ret != 0) {
+        flb_plg_error(ins, "error retrieving overall system CPU stats");
+        return -1;
+    }
+
+    s = snapshot_percent(cstats, ctx);
+
+    ret = flb_log_event_encoder_begin_record(&ctx->log_encoder);
+
+    if (ret == FLB_EVENT_ENCODER_SUCCESS) {
+        ret = flb_log_event_encoder_set_current_timestamp(
+                &ctx->log_encoder);
+    }
+
+    if (ret == FLB_EVENT_ENCODER_SUCCESS) {
+        ret = flb_log_event_encoder_append_body_values(
+                &ctx->log_encoder,
+                FLB_LOG_EVENT_CSTRING_VALUE("cpu_p"),
+                FLB_LOG_EVENT_DOUBLE_VALUE(s[0].p_cpu),
+
+                FLB_LOG_EVENT_CSTRING_VALUE("user_p"),
+                FLB_LOG_EVENT_DOUBLE_VALUE(s[0].p_user),
+
+                FLB_LOG_EVENT_CSTRING_VALUE("system_p"),
+                FLB_LOG_EVENT_DOUBLE_VALUE(s[0].p_system));
+    }
+
+    for (i = 1;
+         i < ctx->n_processors + 1 &&
+         ret == FLB_EVENT_ENCODER_SUCCESS;
+         i++) {
+        struct cpu_snapshot *e = &s[i];
+
+        ret = flb_log_event_encoder_append_body_values(
+                &ctx->log_encoder,
+                FLB_LOG_EVENT_CSTRING_VALUE(e->k_cpu.name),
+                FLB_LOG_EVENT_DOUBLE_VALUE(e->p_cpu),
+
+                FLB_LOG_EVENT_CSTRING_VALUE(e->k_user.name),
+                FLB_LOG_EVENT_DOUBLE_VALUE(e->p_user),
+
+                FLB_LOG_EVENT_CSTRING_VALUE(e->k_system.name),
+                FLB_LOG_EVENT_DOUBLE_VALUE(e->p_system));
+    }
+
+    if (ret == FLB_EVENT_ENCODER_SUCCESS) {
+        ret = flb_log_event_encoder_commit_record(&ctx->log_encoder);
+    }
+
+    snapshots_switch(cstats);
+
+    flb_plg_trace(ins, "CPU %0.2f%%", s->p_cpu);
+
+    if (ret == FLB_EVENT_ENCODER_SUCCESS) {
+        flb_input_log_append(ins, NULL, 0,
+                             ctx->log_encoder.output_buffer,
+                             ctx->log_encoder.output_length);
+        ret = 0;
+    }
+    else {
+        flb_plg_error(ctx->ins, "Error encoding record : %d", ret);
+
+        ret = -1;
+    }
+
+    flb_log_event_encoder_reset(&ctx->log_encoder);
+
+    return ret;
+}
+
+static int cpu_collect_pid(struct flb_input_instance *ins,
+                           struct flb_config *config, void *in_context)
+{
+    int ret;
+    struct flb_cpu *ctx = in_context;
+    struct cpu_stats *cstats = &ctx->cstats;
+    struct cpu_snapshot *s;
+
+    (void) config;
+
+    /* Get overall system CPU usage */
+    ret = proc_cpu_pid_load(ctx, ctx->pid, cstats);
+    if (ret != 0) {
+        flb_plg_error(ctx->ins, "error retrieving PID CPU stats");
+        return -1;
+    }
+
+    s = snapshot_pid_percent(cstats, ctx);
+
+    ret = flb_log_event_encoder_begin_record(&ctx->log_encoder);
+
+    if (ret == FLB_EVENT_ENCODER_SUCCESS) {
+        ret = flb_log_event_encoder_set_current_timestamp(
+                &ctx->log_encoder);
+    }
+
+    if (ret == FLB_EVENT_ENCODER_SUCCESS) {
+        ret = flb_log_event_encoder_append_body_values(
+                &ctx->log_encoder,
+                FLB_LOG_EVENT_CSTRING_VALUE("cpu_p"),
+                FLB_LOG_EVENT_DOUBLE_VALUE(s->p_cpu),
+
+                FLB_LOG_EVENT_CSTRING_VALUE("user_p"),
+                FLB_LOG_EVENT_DOUBLE_VALUE(s->p_user),
+
+                FLB_LOG_EVENT_CSTRING_VALUE("system_p"),
+                FLB_LOG_EVENT_DOUBLE_VALUE(s->p_system));
+    }
+
+    snapshots_switch(cstats);
+    flb_plg_trace(ctx->ins, "PID %i CPU %0.2f%%", ctx->pid, s->p_cpu);
+
+    if (ret == FLB_EVENT_ENCODER_SUCCESS) {
+        ret = flb_log_event_encoder_commit_record(&ctx->log_encoder);
+    }
+
+    if (ret == FLB_EVENT_ENCODER_SUCCESS) {
+        flb_input_log_append(ins, NULL, 0,
+                             ctx->log_encoder.output_buffer,
+                             ctx->log_encoder.output_length);
+
+        ret = 0;
+    }
+    else {
+        flb_plg_error(ctx->ins, "Error encoding record : %d", ret);
+
+        ret = -1;
+    }
+
+    flb_log_event_encoder_reset(&ctx->log_encoder);
+
+    return ret;
+}
+
+/* Callback to gather CPU usage between now and previous snapshot */
+static int cb_cpu_collect(struct flb_input_instance *ins,
+                          struct flb_config *config, void *in_context)
+{
+    struct flb_cpu *ctx = in_context;
+
+    /* if a PID is get, get CPU stats only for that process */
+    if (ctx->pid >= 0) {
+        return cpu_collect_pid(ins, config, in_context);
+    }
+    else {
+        /* Get all system CPU stats */
+        return cpu_collect_system(ins, config, in_context);
+    }
+}
+
+/* Init CPU input */
+static int cb_cpu_init(struct flb_input_instance *in,
+                       struct flb_config *config, void *data)
+{
+    int ret;
+    struct flb_cpu *ctx;
+    (void) data;
+    
+    /* Allocate space for the configuration */
+    ctx = flb_calloc(1, sizeof(struct flb_cpu));
+    if (!ctx) {
+        flb_errno();
+        return -1;
+    }
+    ctx->ins = in;
+    
+    ret = flb_input_config_map_set(in, (void *)ctx);
+    if (ret == -1) {
+        flb_free(ctx);
+        return -1;
+    }
+
+    /* Gather number of processors and CPU ticks */
+    ctx->n_processors = sysconf(_SC_NPROCESSORS_ONLN);
+    ctx->cpu_ticks    = sysconf(_SC_CLK_TCK);
+
+    /* Collection time setting */
+    if (ctx->interval_sec <= 0 && ctx->interval_nsec <= 0) {
+        /* Illegal settings. Override them. */
+        ctx->interval_sec = atoi(DEFAULT_INTERVAL_SEC);
+        ctx->interval_nsec = atoi(DEFAULT_INTERVAL_NSEC);
+    }
+
+    /* Initialize buffers for CPU stats */
+    ret = snapshots_init(ctx->n_processors, &ctx->cstats);
+    if (ret != 0) {
+        flb_free(ctx);
+        return -1;
+    }
+
+    /* Get CPU load, ready to be updated once fired the calc callback */
+    if (ctx->pid > 0) {
+        ret = proc_cpu_pid_load(ctx, ctx->pid, &ctx->cstats);
+    }
+    else {
+        ret = proc_cpu_load(ctx->n_processors, &ctx->cstats);
+    }
+    if (ret != 0) {
+        flb_error("[cpu] Could not obtain CPU data");
+        flb_free(ctx);
+        return -1;
+    }
+
+    ctx->cstats.snap_active = CPU_SNAP_ACTIVE_B;
+
+    /* Set the context */
+    flb_input_set_context(in, ctx);
+
+    /* Set our collector based on time, CPU usage every 1 second */
+    ret = flb_input_set_collector_time(in,
+                                       cb_cpu_collect,
+                                       ctx->interval_sec,
+                                       ctx->interval_nsec,
+                                       config);
+    if (ret == -1) {
+        flb_plg_error(ctx->ins, "could not set collector for CPU input plugin");
+        return -1;
+    }
+    ctx->coll_fd = ret;
+
+    ret = flb_log_event_encoder_init(&ctx->log_encoder,
+                                     FLB_LOG_EVENT_FORMAT_DEFAULT);
+
+    if (ret != FLB_EVENT_ENCODER_SUCCESS) {
+        flb_plg_error(ctx->ins, "error initializing event encoder : %d", ret);
+
+        /* Release snapshots */
+        flb_free(ctx->cstats.snap_a);
+        flb_free(ctx->cstats.snap_b);
+
+        /* done */
+        flb_free(ctx);
+
+        return -1;
+    }
+
+    return 0;
+}
+
+static void cb_cpu_pause(void *data, struct flb_config *config)
+{
+    struct flb_cpu *ctx = data;
+    flb_input_collector_pause(ctx->coll_fd, ctx->ins);
+}
+
+static void cb_cpu_resume(void *data, struct flb_config *config)
+{
+    struct flb_cpu *ctx = data;
+    flb_input_collector_resume(ctx->coll_fd, ctx->ins);
+}
+
+static int cb_cpu_exit(void *data, struct flb_config *config)
+{
+    (void) *config;
+    struct flb_cpu *ctx = data;
+    struct cpu_stats *cs;
+
+    flb_log_event_encoder_destroy(&ctx->log_encoder);
+
+    /* Release snapshots */
+    cs = &ctx->cstats;
+    flb_free(cs->snap_a);
+    flb_free(cs->snap_b);
+
+    /* done */
+    flb_free(ctx);
+
+    return 0;
+}
+
+/* Configuration properties map */
+static struct flb_config_map config_map[] = {
+    {
+     FLB_CONFIG_MAP_INT, "pid", "-1",
+     0, FLB_TRUE, offsetof(struct flb_cpu, pid),
+     "Configure a single process to measure usage via their PID"
+    },
+    {
+      FLB_CONFIG_MAP_INT, "interval_sec", DEFAULT_INTERVAL_SEC,
+      0, FLB_TRUE, offsetof(struct flb_cpu, interval_sec),
+      "Set the collector interval"
+    },
+    {
+      FLB_CONFIG_MAP_INT, "interval_nsec", DEFAULT_INTERVAL_NSEC,
+      0, FLB_TRUE, offsetof(struct flb_cpu, interval_nsec),
+      "Set the collector interval (sub seconds)"
+    },
+    /* EOF */
+    {0}
+};
+
+/* Plugin reference */
+struct flb_input_plugin in_cpu_plugin = {
+    .name         = "cpu",
+    .description  = "CPU Usage",
+    .cb_init      = cb_cpu_init,
+    .cb_pre_run   = NULL,
+    .cb_collect   = cb_cpu_collect,
+    .cb_flush_buf = NULL,
+    .config_map   = config_map,
+    .cb_pause     = cb_cpu_pause,
+    .cb_resume    = cb_cpu_resume,
+    .cb_exit      = cb_cpu_exit
+};
diff --git a/fluent-bit/plugins/in_cpu/cpu.h b/fluent-bit/plugins/in_cpu/cpu.h
new file mode 100644
index 00000000..93cbd88c
--- /dev/null
+++ b/fluent-bit/plugins/in_cpu/cpu.h
@@ -0,0 +1,129 @@
+/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+
+/*  Fluent Bit
+ *  ==========
+ *  Copyright (C) 2015-2022 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_IN_CPU_H
+#define FLB_IN_CPU_H
+
+#include <fluent-bit/flb_config.h>
+#include <fluent-bit/flb_input.h>
+#include <fluent-bit/flb_utils.h>
+#include <fluent-bit/flb_log_event_encoder.h>
+
+/* Default collection time: every 1 second (0 nanoseconds) */
+#define DEFAULT_INTERVAL_SEC    "1"
+#define DEFAULT_INTERVAL_NSEC   "0"
+#define IN_CPU_KEY_LEN       16
+
+struct cpu_key {
+    uint8_t length;
+    char name[IN_CPU_KEY_LEN];
+};
+
+struct cpu_snapshot {
+    /* data snapshots */
+    char          v_cpuid[8];
+    unsigned long v_user;
+    unsigned long v_nice;
+    unsigned long v_system;
+    unsigned long v_idle;
+    unsigned long v_iowait;
+
+    /* percent values */
+    double p_cpu;           /* Overall CPU usage        */
+    double p_user;          /* user space (user + nice) */
+    double p_system;        /* kernel space percent     */
+
+    /* necessary... */
+    struct cpu_key k_cpu;
+    struct cpu_key k_user;
+    struct cpu_key k_system;
+};
+
+#define CPU_SNAP_ACTIVE_A    0
+#define CPU_SNAP_ACTIVE_B    1
+
+struct cpu_stats {
+    uint8_t snap_active;
+
+    /* CPU snapshots, we always keep two snapshots */
+    struct cpu_snapshot *snap_a;
+    struct cpu_snapshot *snap_b;
+};
+
+/* CPU Input configuration & context */
+struct flb_cpu {
+    /* setup */
+    pid_t pid;          /* optional PID */
+    int n_processors;   /* number of core processors  */
+    int cpu_ticks;      /* CPU ticks (Kernel setting) */
+    int coll_fd;        /* collector id/fd            */
+    int interval_sec;   /* interval collection time (Second) */
+    int interval_nsec;  /* interval collection time (Nanosecond) */
+    struct cpu_stats cstats;
+    struct flb_input_instance *ins;
+    struct flb_log_event_encoder log_encoder;
+};
+
+#define CPU_KEY_FORMAT(s, key, i)                                   \
+    s->k_##key.length = snprintf(s->k_##key.name,                   \
+                                 IN_CPU_KEY_LEN,                    \
+                                 "cpu%i.p_%s", i - 1, #key)
+
+#define ULL_ABS(a, b)  (a > b) ? a - b : b - a
+
+/*
+ * This routine calculate the average CPU utilization of the system, it
+ * takes in consideration the number CPU cores, so it return a value
+ * between 0 and 100 based on 'capacity'.
+ */
+static inline double CPU_METRIC_SYS_AVERAGE(unsigned long pre,
+                                            unsigned long now,
+                                            struct flb_cpu *ctx)
+{
+    double diff;
+    double total = 0;
+
+    if (pre == now) {
+        return 0.0;
+    }
+
+    diff = ULL_ABS(now, pre);
+    total = (((diff / ctx->cpu_ticks) * 100) / ctx->n_processors) / (ctx->interval_sec + 1e-9*ctx->interval_nsec);
+
+    return total;
+}
+
+/* Returns the CPU % utilization of a given CPU core */
+static inline double CPU_METRIC_USAGE(unsigned long pre, unsigned long now,
+                                      struct flb_cpu *ctx)
+{
+    double diff;
+    double total = 0;
+
+    if (pre == now) {
+        return 0.0;
+    }
+
+    diff = ULL_ABS(now, pre);
+
+    total = ((diff * 100) / ctx->cpu_ticks) / (ctx->interval_sec + 1e-9*ctx->interval_nsec);
+    return total;
+}
+
+#endif