influxdb.h

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#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <sys/uio.h>
#include <netdb.h>
#include <stdarg.h>
#include <string.h>
#include <stdio.h>
#include <unistd.h>
#include <curl/curl.h>
 
#define INFLUX_MEAS(m) IF_TYPE_MEAS, (m)
#define INFLUX_TAG(k, v) IF_TYPE_TAG, (k), (v)
#define INFLUX_F_STR(k, v) IF_TYPE_FIELD_STRING, (k), (v)
#define INFLUX_F_FLT(k, v, p) IF_TYPE_FIELD_FLOAT, (k), (double)(v), (int)(p)
#define INFLUX_F_INT(k, v) IF_TYPE_FIELD_INTEGER, (k), (long long)(v)
#define INFLUX_F_BOL(k, v) IF_TYPE_FIELD_BOOLEAN, (k), ((v) ? 1 : 0)
#define INFLUX_TS(ts) IF_TYPE_TIMESTAMP, (long long)(ts)
#define INFLUX_END IF_TYPE_ARG_END

typedef struct influx_client_t {
  char* host;
  int port;
  char* db;    // http only
  char* usr;   // http only [optional for auth]
  char* pwd;   // http only [optional for auth]
  char* token; // http only
} influx_client_t;

typedef struct influx_v2_client_t {
  char* host;
  int port;
  char* org;
  char* bucket;
  char* precision;
  char* usr;   // http only [optional for auth]
  char* pwd;   // http only [optional for auth]
  char* token; // http only
} influx_v2_client_t;

int format_line(char** buf, int* len, size_t used, ...);

int post_http(influx_client_t* c, ...);

int send_udp(influx_client_t* c, ...);

int post_curl(influx_v2_client_t* c, ...);
 
#define IF_TYPE_ARG_END 0
#define IF_TYPE_MEAS 1
#define IF_TYPE_TAG 2
#define IF_TYPE_FIELD_STRING 3
#define IF_TYPE_FIELD_FLOAT 4
#define IF_TYPE_FIELD_INTEGER 5
#define IF_TYPE_FIELD_BOOLEAN 6
#define IF_TYPE_TIMESTAMP 7
 
int _escaped_append(char** dest, size_t* len, size_t* used, const char* src, const char* escape_seq);
int _begin_line(char** buf);
int _format_line(char** buf, va_list ap);
int _format_line2(char** buf, va_list ap, size_t*, size_t);

int post_http_send_line(influx_client_t* c, char* buf, int len);

int send_udp_line(influx_client_t* c, char* line, int len);
 
int post_http_send_line(influx_client_t* c, char* buf, int len) {
  int sock = -1, ret_code = 0, content_length = 0;
  struct sockaddr_in addr;
  struct iovec iv[2];
  char ch;
 
  iv[1].iov_base = buf;
  iv[1].iov_len = len;
 
  if (!(iv[0].iov_base = (char*)malloc(len = 0x800))) {
    free(iv[1].iov_base);
    return -2;
  }
 
  for (;;) {
    iv[0].iov_len =
        snprintf((char*)iv[0].iov_base, len,
                 "POST /write?db=%s&u=%s&p=%s HTTP/1.1\r\n"
                 "Host: %s\r\n"
                 "Accept: application/json\r\n"
                 "Content-type: text/plain\r\n"
                 "Authorization: Token %s\r\n"
                 "Content-Length: %zd\r\n"
                 "\r\n", // Final blank line is needed.
                 c->db, c->usr ? c->usr : "", c->pwd ? c->pwd : "", c->host, c->token ? c->token : "", iv[1].iov_len);
    if ((int)iv[0].iov_len >= len && !(iv[0].iov_base = (char*)realloc(iv[0].iov_base, len *= 2))) {
      free(iv[1].iov_base);
      free(iv[0].iov_base);
      return -3;
    } else
      break;
  }
 
  fprintf(stderr, "influxdb-c::post_http: iv[0] = '%s'\n", (char*)iv[0].iov_base);
  fprintf(stderr, "influxdb-c::post_http: iv[1] = '%s'\n", (char*)iv[1].iov_base);
 
  addr.sin_family = AF_INET;
  addr.sin_port = htons(c->port);
  // EAL: Rather than just an IP address, allow a hostname, like "localhost"
  struct hostent* resolved_host = gethostbyname(c->host);
  if (!resolved_host) {
    free(iv[1].iov_base);
    free(iv[0].iov_base);
    return -4;
  }
  memcpy(&addr.sin_addr, resolved_host->h_addr_list[0], resolved_host->h_length);
  /*
  if((addr.sin_addr.s_addr = inet_addr(resolved_host->h_addr)) == INADDR_NONE) {
      free(iv[1].iov_base);
      free(iv[0].iov_base);
      return -4;
  }
  */
 
  if ((sock = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
    free(iv[1].iov_base);
    free(iv[0].iov_base);
    return -5;
  }
 
  if (connect(sock, (struct sockaddr*)(&addr), sizeof(addr)) < 0) {
    ret_code = -6;
    goto END;
  }
 
  if (writev(sock, iv, 2) < (int)(iv[0].iov_len + iv[1].iov_len)) {
    ret_code = -7;
    goto END;
  }
  iv[0].iov_len = len;
 
#define _GET_NEXT_CHAR()                                                                                               \
  (ch = (len >= (int)iv[0].iov_len &&                                                                                  \
                 (iv[0].iov_len = recv(sock, iv[0].iov_base, iv[0].iov_len, len = 0)) == (size_t)(-1)                  \
             ? 0                                                                                                       \
             : *((char*)iv[0].iov_base + len++)))
#define _LOOP_NEXT(statement)                                                                                          \
  for (;;) {                                                                                                           \
    if (!(_GET_NEXT_CHAR())) {                                                                                         \
      ret_code = -8;                                                                                                   \
      goto END;                                                                                                        \
    }                                                                                                                  \
    statement                                                                                                          \
  }
#define _UNTIL(c) _LOOP_NEXT(if (ch == c) break;)
#define _GET_NUMBER(n) _LOOP_NEXT(if (ch >= '0' && ch <= '9') n = n * 10 + (ch - '0'); else break;)
#define _(c)                                                                                                           \
  if ((_GET_NEXT_CHAR()) != c)                                                                                         \
    break;
 
  _UNTIL(' ') _GET_NUMBER(ret_code) for (;;) {
    _UNTIL('\n')
    switch (_GET_NEXT_CHAR()) {
    case 'C':
      _('o')
      _('n')
      _('t')
      _('e')
      _('n') _('t') _('-') _('L') _('e') _('n') _('g') _('t') _('h') _(':') _(' ') _GET_NUMBER(content_length) break;
    case '\r':
      _('\n')
      while (content_length-- > 0 && _GET_NEXT_CHAR())
        ; // printf("%c", ch);
      goto END;
    }
    if (!ch) {
      ret_code = -10;
      goto END;
    }
  }
  ret_code = -11;
END:
  close(sock);
  free(iv[0].iov_base);
  free(iv[1].iov_base);
  return ret_code / 100 == 2 ? 0 : ret_code;
}
#undef _GET_NEXT_CHAR
#undef _LOOP_NEXT
#undef _UNTIL
#undef _GET_NUMBER
#undef _
 
int post_http(influx_client_t* c, ...) {
  va_list ap;
  char* line = NULL;
  int ret_code = 0, len = 0;
 
  va_start(ap, c);
  len = _format_line((char**)&line, ap);
  va_end(ap);
  if (len < 0)
    return -1;
 
  ret_code = post_http_send_line(c, line, len);
 
  return ret_code;
}
 
int send_udp_line(influx_client_t* c, char* line, int len) {
  int sock = -1, ret = 0;
  struct sockaddr_in addr;
 
  addr.sin_family = AF_INET;
  addr.sin_port = htons(c->port);
  if ((addr.sin_addr.s_addr = inet_addr(c->host)) == INADDR_NONE) {
    ret = -2;
    goto END;
  }
 
  if ((sock = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
    ret = -3;
    goto END;
  }
 
  if (sendto(sock, line, len, 0, (struct sockaddr*)&addr, sizeof(addr)) < len)
    ret = -4;
 
END:
  if (sock >= 0) {
    close(sock);
  }
  return ret;
}
 
int send_udp(influx_client_t* c, ...) {
  int ret = 0, len;
  va_list ap;
  char* line = NULL;
 
  va_start(ap, c);
  len = _format_line(&line, ap);
  va_end(ap);
  if (len < 0)
    return -1;
 
  ret = send_udp_line(c, line, len);
 
  free(line);
  return ret;
}
 
int post_curl(influx_v2_client_t* c, ...) {
  va_list ap;
  char* data = NULL;
  int len = 0;
  va_start(ap, c);
  len = _format_line((char**)&data, ap);
  va_end(ap);
 
  CURL* curl;
 
  /* In windows, this will init the winsock stuff */
  curl_global_init(CURL_GLOBAL_ALL);
  CURLcode res;
 
  /* get a curl handle */
  curl = curl_easy_init();
  if (!curl) {
    return CURLE_FAILED_INIT;
  }
 
  char* url_string = (char*)malloc(len);
  snprintf(url_string, len, "http://%s:%d/api/v2/write?org=%s&bucket=%s&precision=%s", c->host ? c->host : "localhost",
           c->port ? c->port : 8086, c->org, c->bucket, c->precision ? c->precision : "ns");
 
  curl_easy_setopt(curl, CURLOPT_URL, url_string);
  free(url_string);
 
  char token_string[120];
  snprintf(token_string, sizeof(token_string), "Authorization: Token %s", c->token);
 
  struct curl_slist* list = NULL;
  list = curl_slist_append(list, token_string);
  curl_easy_setopt(curl, CURLOPT_HTTPHEADER, list);
 
  curl_easy_setopt(curl, CURLOPT_POSTFIELDS, data);
  curl_easy_setopt(curl, CURLOPT_USERAGENT, "libcurl-agent/1.0");
 
  /* Perform the request, res will get the return code */
  res = curl_easy_perform(curl);
  /* Check for errors */
  if (res != CURLE_OK) {
    fprintf(stderr, "curl_easy_perform() failed: %s\n", curl_easy_strerror(res));
  }
 
  free(data);
  curl_easy_cleanup(curl);
  curl_global_cleanup();
  return res;
}
 
int format_line(char** buf, int* len, size_t used, ...) {
  va_list ap;
  va_start(ap, used);
  used = _format_line2(buf, ap, (size_t*)len, used);
  va_end(ap);
  if (*len < 0)
    return -1;
  else
    return used;
}
 
int _begin_line(char** buf) {
  int len = 0x100;
  if (!(*buf = (char*)malloc(len)))
    return -1;
  return len;
}
 
int _format_line(char** buf, va_list ap) {
  size_t len = 0;
  *buf = NULL;
  return _format_line2(buf, ap, &len, 0);
}
 
int _format_line2(char** buf, va_list ap, size_t* _len, size_t used) {
#define _APPEND(fmter...)                                                                                              \
  for (;;) {                                                                                                           \
    if ((written = snprintf(*buf + used, len - used, ##fmter)) < 0)                                                    \
      goto FAIL;                                                                                                       \
    if (used + written >= len && !(*buf = (char*)realloc(*buf, len *= 2)))                                             \
      return -1;                                                                                                       \
    else {                                                                                                             \
      used += written;                                                                                                 \
      break;                                                                                                           \
    }                                                                                                                  \
  }
 
  size_t len = *_len;
  int written = 0, type = 0, last_type = 0;
  unsigned long long i = 0;
  double d = 0.0;
 
  if (*buf == NULL) {
    len = _begin_line(buf);
    used = 0;
  }
 
  type = va_arg(ap, int);
  while (type != IF_TYPE_ARG_END) {
    if (type >= IF_TYPE_TAG && type <= IF_TYPE_FIELD_BOOLEAN) {
      if (last_type < IF_TYPE_MEAS || last_type > (type == IF_TYPE_TAG ? IF_TYPE_TAG : IF_TYPE_FIELD_BOOLEAN))
        goto FAIL;
      _APPEND("%c", (last_type <= IF_TYPE_TAG && type > IF_TYPE_TAG) ? ' ' : ',');
      if (_escaped_append(buf, &len, &used, va_arg(ap, char*), ",= "))
        return -2;
      _APPEND("=");
    }
    switch (type) {
    case IF_TYPE_MEAS:
      if (last_type)
        _APPEND("\n");
      if (last_type && last_type <= IF_TYPE_TAG)
        goto FAIL;
      if (_escaped_append(buf, &len, &used, va_arg(ap, char*), ", "))
        return -3;
      break;
    case IF_TYPE_TAG:
      if (_escaped_append(buf, &len, &used, va_arg(ap, char*), ",= "))
        return -4;
      break;
    case IF_TYPE_FIELD_STRING:
      _APPEND("\"");
      if (_escaped_append(buf, &len, &used, va_arg(ap, char*), "\""))
        return -5;
      _APPEND("\"");
      break;
    case IF_TYPE_FIELD_FLOAT:
      d = va_arg(ap, double);
      i = va_arg(ap, int);
      _APPEND("%.*lf", (int)i, d);
      break;
    case IF_TYPE_FIELD_INTEGER:
      i = va_arg(ap, long long);
      _APPEND("%lldi", i);
      break;
    case IF_TYPE_FIELD_BOOLEAN:
      i = va_arg(ap, int);
      _APPEND("%c", i ? 't' : 'f');
      break;
    case IF_TYPE_TIMESTAMP:
      if (last_type < IF_TYPE_FIELD_STRING || last_type > IF_TYPE_FIELD_BOOLEAN)
        goto FAIL;
      i = va_arg(ap, long long);
      _APPEND(" %lld", i);
      break;
    default:
      goto FAIL;
    }
    last_type = type;
    type = va_arg(ap, int);
  }
  _APPEND("\n");
  if (last_type <= IF_TYPE_TAG)
    goto FAIL;
  *_len = len;
  return used;
FAIL:
  free(*buf);
  *buf = NULL;
  return -1;
}
#undef _APPEND
 
int _escaped_append(char** dest, size_t* len, size_t* used, const char* src, const char* escape_seq) {
  size_t i = 0;
 
  for (;;) {
    if ((i = strcspn(src, escape_seq)) > 0) {
      if (*used + i > *len && !(*dest = (char*)realloc(*dest, (*len) *= 2)))
        return -1;
      strncpy(*dest + *used, src, i);
      *used += i;
      src += i;
    }
    if (*src) {
      if (*used + 2 > *len && !(*dest = (char*)realloc(*dest, (*len) *= 2)))
        return -2;
      (*dest)[(*used)++] = '\\';
      (*dest)[(*used)++] = *src++;
    } else
      return 0;
  }
  return 0;
}