4192383612

Build # 4192383612

Build Type

github

Committed by GitHub

Commit Message

Merge 039bc354a into 1833c1848

Pull Request Pull Request #634: Update deps

Run Details

773 of 802 relevant lines covered (96.38%)

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93.55

/pull/src/handler.cc

#include "handler.h"

#include <algorithm>
#include <chrono>
#include <cstring>
#include <iterator>
#include <string>

#ifdef HAVE_ZLIB
#include <zconf.h>
#include <zlib.h>
#endif

#include "civetweb.h"
#include "metrics_collector.h"
#include "prometheus/counter.h"
#include "prometheus/metric_family.h"
#include "prometheus/summary.h"
#include "prometheus/text_serializer.h"

namespace prometheus {
namespace detail {

MetricsHandler::MetricsHandler(Registry& registry)
    : bytes_transferred_family_(
          BuildCounter()
              .Name("exposer_transferred_bytes_total")
              .Help("Transferred bytes to metrics services")
              .Register(registry)),
      bytes_transferred_(bytes_transferred_family_.Add({})),
      num_scrapes_family_(BuildCounter()
                              .Name("exposer_scrapes_total")
                              .Help("Number of times metrics were scraped")
                              .Register(registry)),
      num_scrapes_(num_scrapes_family_.Add({})),
      request_latencies_family_(
          BuildSummary()
              .Name("exposer_request_latencies")
              .Help("Latencies of serving scrape requests, in microseconds")
              .Register(registry)),
      request_latencies_(request_latencies_family_.Add(
          {}, Summary::Quantiles{{0.5, 0.05}, {0.9, 0.01}, {0.99, 0.001}})) {}

#ifdef HAVE_ZLIB
static bool IsEncodingAccepted(struct mg_connection* conn,
                               const char* encoding) {
  auto accept_encoding = mg_get_header(conn, "Accept-Encoding");
  if (!accept_encoding) {
    return false;
  }
  return std::strstr(accept_encoding, encoding) != nullptr;
}

static std::vector<Byte> GZipCompress(const std::string& input) {
  auto zs = z_stream{};
  auto windowSize = 16 + MAX_WBITS;
  auto memoryLevel = 9;

  if (deflateInit2(&zs, Z_DEFAULT_COMPRESSION, Z_DEFLATED, windowSize,
                   memoryLevel, Z_DEFAULT_STRATEGY) != Z_OK) {
    return {};
  }

  zs.next_in = (Bytef*)input.data();
  zs.avail_in = input.size();

  int ret;
  std::vector<Byte> output;
  output.reserve(input.size() / 2u);

  do {
    static const auto outputBytesPerRound = std::size_t{32768};

    zs.avail_out = outputBytesPerRound;
    output.resize(zs.total_out + zs.avail_out);
    zs.next_out = reinterpret_cast<Bytef*>(output.data() + zs.total_out);

    ret = deflate(&zs, Z_FINISH);

    output.resize(zs.total_out);
  } while (ret == Z_OK);

  deflateEnd(&zs);

  if (ret != Z_STREAM_END) {
    return {};
  }

  return output;
}
#endif

static std::size_t WriteResponse(struct mg_connection* conn,
                                 const std::string& body) {
  mg_printf(conn,
            "HTTP/1.1 200 OK\r\n"
            "Content-Type: text/plain; charset=utf-8\r\n");

#ifdef HAVE_ZLIB
  auto acceptsGzip = IsEncodingAccepted(conn, "gzip");

  if (acceptsGzip) {
    auto compressed = GZipCompress(body);
    if (!compressed.empty()) {
      mg_printf(conn,
                "Content-Encoding: gzip\r\n"
                "Content-Length: %lu\r\n\r\n",
                static_cast<unsigned long>(compressed.size()));
      mg_write(conn, compressed.data(), compressed.size());
      return compressed.size();
    }
  }
#endif

  mg_printf(conn, "Content-Length: %lu\r\n\r\n",
            static_cast<unsigned long>(body.size()));
  mg_write(conn, body.data(), body.size());
  return body.size();
}

void MetricsHandler::RegisterCollectable(
    const std::weak_ptr<Collectable>& collectable) {
  std::lock_guard<std::mutex> lock{collectables_mutex_};
  CleanupStalePointers(collectables_);
  collectables_.push_back(collectable);
}

void MetricsHandler::RemoveCollectable(
    const std::weak_ptr<Collectable>& collectable) {
  std::lock_guard<std::mutex> lock{collectables_mutex_};

  auto locked = collectable.lock();
  auto same_pointer = [&locked](const std::weak_ptr<Collectable>& candidate) {
    return locked == candidate.lock();
  };

  collectables_.erase(std::remove_if(std::begin(collectables_),
                                     std::end(collectables_), same_pointer),
                      std::end(collectables_));
}

bool MetricsHandler::handleGet(CivetServer*, struct mg_connection* conn) {
  auto start_time_of_request = std::chrono::steady_clock::now();

  std::vector<MetricFamily> metrics;

  {
    std::lock_guard<std::mutex> lock{collectables_mutex_};
    metrics = CollectMetrics(collectables_);
  }

  const TextSerializer serializer;

  auto bodySize = WriteResponse(conn, serializer.Serialize(metrics));

  auto stop_time_of_request = std::chrono::steady_clock::now();
  auto duration = std::chrono::duration_cast<std::chrono::microseconds>(
      stop_time_of_request - start_time_of_request);
  request_latencies_.Observe(duration.count());

  bytes_transferred_.Increment(bodySize);
  num_scrapes_.Increment();
  return true;
}

void MetricsHandler::CleanupStalePointers(
    std::vector<std::weak_ptr<Collectable>>& collectables) {
  collectables.erase(
      std::remove_if(std::begin(collectables), std::end(collectables),
                     [](const std::weak_ptr<Collectable>& candidate) {
                       return candidate.expired();
                     }),
      std::end(collectables));
}
}  // namespace detail
}  // namespace prometheus

1	#include "handler.h"
2
3	#include <algorithm>
4	#include <chrono>
5	#include <cstring>
6	#include <iterator>
7	#include <string>
8
9	#ifdef HAVE_ZLIB
10	#include <zconf.h>
11	#include <zlib.h>
12	#endif
13
14	#include "civetweb.h"
15	#include "metrics_collector.h"
16	#include "prometheus/counter.h"
17	#include "prometheus/metric_family.h"
18	#include "prometheus/summary.h"
19	#include "prometheus/text_serializer.h"
20
21	namespace prometheus {
22	namespace detail {
23
24	MetricsHandler::MetricsHandler(Registry& registry)	16✔
25	: bytes_transferred_family_(
26	BuildCounter()	16✔
27	.Name("exposer_transferred_bytes_total")	32✔
28	.Help("Transferred bytes to metrics services")	32✔
29	.Register(registry)),	16✔
30	bytes_transferred_(bytes_transferred_family_.Add({})),	16✔
31	num_scrapes_family_(BuildCounter()	16✔
32	.Name("exposer_scrapes_total")	32✔
33	.Help("Number of times metrics were scraped")	32✔
34	.Register(registry)),	16✔
35	num_scrapes_(num_scrapes_family_.Add({})),	16✔
36	request_latencies_family_(
37	BuildSummary()	16✔
38	.Name("exposer_request_latencies")	32✔
39	.Help("Latencies of serving scrape requests, in microseconds")	32✔
40	.Register(registry)),	16✔
41	request_latencies_(request_latencies_family_.Add(	16✔
42	{}, Summary::Quantiles{{0.5, 0.05}, {0.9, 0.01}, {0.99, 0.001}})) {}	112✔
43
44	#ifdef HAVE_ZLIB
45	static bool IsEncodingAccepted(struct mg_connection* conn,	16✔
46	const char* encoding) {
47	auto accept_encoding = mg_get_header(conn, "Accept-Encoding");	16✔
48	if (!accept_encoding) {	16✔
49	return false;	14✔
50	}
51	return std::strstr(accept_encoding, encoding) != nullptr;	2✔
52	}
53
54	static std::vector<Byte> GZipCompress(const std::string& input) {	2✔
55	auto zs = z_stream{};	2✔
56	auto windowSize = 16 + MAX_WBITS;	2✔
57	auto memoryLevel = 9;	2✔
58
59	if (deflateInit2(&zs, Z_DEFAULT_COMPRESSION, Z_DEFLATED, windowSize,	2✔
60	memoryLevel, Z_DEFAULT_STRATEGY) != Z_OK) {	2✔
61	return {};	×
62	}
63
64	zs.next_in = (Bytef*)input.data();	2✔
65	zs.avail_in = input.size();	2✔
66
67	int ret;
68	std::vector<Byte> output;	4✔
69	output.reserve(input.size() / 2u);	2✔
70
71	do {	×
72	static const auto outputBytesPerRound = std::size_t{32768};
73
74	zs.avail_out = outputBytesPerRound;	2✔
75	output.resize(zs.total_out + zs.avail_out);	2✔
76	zs.next_out = reinterpret_cast<Bytef*>(output.data() + zs.total_out);	2✔
77
78	ret = deflate(&zs, Z_FINISH);	2✔
79
80	output.resize(zs.total_out);	2✔
81	} while (ret == Z_OK);	2✔
82
83	deflateEnd(&zs);	2✔
84
85	if (ret != Z_STREAM_END) {	2✔
86	return {};	×
87	}
88
89	return output;	2✔
90	}
91	#endif
92
93	static std::size_t WriteResponse(struct mg_connection* conn,	16✔
94	const std::string& body) {
95	mg_printf(conn,	16✔
96	"HTTP/1.1 200 OK\r\n"
97	"Content-Type: text/plain; charset=utf-8\r\n");
98
99	#ifdef HAVE_ZLIB
100	auto acceptsGzip = IsEncodingAccepted(conn, "gzip");	16✔
101
102	if (acceptsGzip) {	16✔
103	auto compressed = GZipCompress(body);	2✔
104	if (!compressed.empty()) {	2✔
105	mg_printf(conn,	2✔
106	"Content-Encoding: gzip\r\n"
107	"Content-Length: %lu\r\n\r\n",
108	static_cast<unsigned long>(compressed.size()));	2✔
109	mg_write(conn, compressed.data(), compressed.size());	2✔
110	return compressed.size();	2✔
111	}
112	}
113	#endif
114
115	mg_printf(conn, "Content-Length: %lu\r\n\r\n",	14✔
116	static_cast<unsigned long>(body.size()));	14✔
117	mg_write(conn, body.data(), body.size());	14✔
118	return body.size();	14✔
119	}
120
121	void MetricsHandler::RegisterCollectable(	34✔
122	const std::weak_ptr<Collectable>& collectable) {
123	std::lock_guard<std::mutex> lock{collectables_mutex_};	68✔
124	CleanupStalePointers(collectables_);	34✔
125	collectables_.push_back(collectable);	34✔
126	}	34✔
127
128	void MetricsHandler::RemoveCollectable(	2✔
129	const std::weak_ptr<Collectable>& collectable) {
130	std::lock_guard<std::mutex> lock{collectables_mutex_};	4✔
131
132	auto locked = collectable.lock();	2✔
133	auto same_pointer = [&locked](const std::weak_ptr<Collectable>& candidate) {	8✔
134	return locked == candidate.lock();	4✔
135	};	2✔
136
137	collectables_.erase(std::remove_if(std::begin(collectables_),	×
138	std::end(collectables_), same_pointer),	2✔
139	std::end(collectables_));	4✔
140	}	2✔
141
142	bool MetricsHandler::handleGet(CivetServer, struct mg_connection conn) {	16✔
143	auto start_time_of_request = std::chrono::steady_clock::now();	16✔
144
145	std::vector<MetricFamily> metrics;	32✔
146
147	{
148	std::lock_guard<std::mutex> lock{collectables_mutex_};	16✔
149	metrics = CollectMetrics(collectables_);	16✔
150	}
151
152	const TextSerializer serializer;	×
153
154	auto bodySize = WriteResponse(conn, serializer.Serialize(metrics));	16✔
155
156	auto stop_time_of_request = std::chrono::steady_clock::now();	16✔
157	auto duration = std::chrono::duration_cast<std::chrono::microseconds>(
158	stop_time_of_request - start_time_of_request);	16✔
159	request_latencies_.Observe(duration.count());	16✔
160
161	bytes_transferred_.Increment(bodySize);	16✔
162	num_scrapes_.Increment();	16✔
163	return true;	32✔
164	}
165
166	void MetricsHandler::CleanupStalePointers(	34✔
167	std::vector<std::weak_ptr<Collectable>>& collectables) {
168	collectables.erase(
169	std::remove_if(std::begin(collectables), std::end(collectables),	×
170	[](const std::weak_ptr<Collectable>& candidate) {	20✔
171	return candidate.expired();	20✔
172	}),	34✔
173	std::end(collectables));	68✔
174	}	34✔
175	} // namespace detail
176	} // namespace prometheus

jupp0r / prometheus-cpp / 4192383612

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