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#include "web.h"
#include "db.h"
#include <algorithm>
#include <vector>
#include <leveldb/comparator.h>
#include <iomanip>
static const leveldb::Comparator *cmp = leveldb::BytewiseComparator();
static inline std::string make_key(uint64_t timestamp) {
std::stringstream key;
key << "ts-";
key << std::setfill('0') << std::setw(20) << timestamp;
return key.str();
}
static inline bool parse_key(leveldb::Slice &&key, uint64_t *value) {
if (key.size() != 20+3)
return false;
*value = std::stoul(key.data()+3);
return true;
}
const boost::regex web_handle_api_value_R(
"/api/value/([a-zA-Z0-9\\.]+)/([0-9]+)");
void web_handle_api_value(const boost::cmatch &match, struct mg_connection *conn) {
std::string sensor(match[1].str());
uint64_t timestamp = std::stoul(match[2].str());
char buf[1024];
int count = mg_read(conn, buf, 1024);
std::string value(buf, count);
leveldb::DB *db = getDB(sensor);
if (db == nullptr) {
std::cout << "failed to get db for " << sensor << std::endl;
mg_printf(conn, "HTTP/1.1 500 Internal Error\r\n\r\n");
return;
}
db->Put(leveldb::WriteOptions(), make_key(timestamp), value);
mg_printf(conn, "HTTP/1.1 200 Value received\r\n\r\n");
}
static inline void print_json_tuple(struct mg_connection *conn,
std::ostringstream &outbuf,
leveldb::Slice &&key,
leveldb::Slice &&value) {
size_t key_size = key.size();
if (key_size != 20+3) {
std::cerr << "invalid key" << std::endl;
return;
}
unsigned int offset = 3; // "ts-"
// skip zeros in timestamp
while (offset < key_size-1 and *(key.data()+offset) == '0')
offset++;
outbuf << '[';
outbuf.write(key.data()+offset, key_size-offset);
outbuf << ',';
outbuf.write(value.data(), value.size());
outbuf << ']';
mg_write(conn, outbuf.str().c_str(), outbuf.tellp());
}
const boost::regex web_handle_api_range_R(
"/api/range/([a-zA-Z0-9\\.]+)/([0-9]+)/([0-9]+)");
void web_handle_api_range(const boost::cmatch &match, struct mg_connection *conn) {
std::string sensor(match[1].str());
uint64_t start = std::stoul(match[2].str());
uint64_t end = std::stoul(match[3].str());
std::string key_start(std::move(make_key(start)));
std::string key_end(std::move(make_key(end)));
leveldb::DB *db = getDB(sensor);
if (db == nullptr) {
mg_printf(conn, "HTTP/1.1 500 Internal Error\r\n"
"\r\n");
return;
}
mg_printf(conn,
"HTTP/1.1 200 OK\r\n"
"Content-Type: application/json\r\n"
"\r\n");
std::ostringstream out;
out << "{\"sensor\":\"" << sensor << "\", "
<< "\"error\":null, "
<< "\"data\":[";
mg_write(conn, out.str().c_str(), out.str().size());
leveldb::Iterator* it = db->NewIterator(leveldb::ReadOptions());
bool first = true;
std::ostringstream outbuf;
for (it->Seek(key_start);
it->Valid() && cmp->Compare(it->key(), key_end) < 0;
it->Next()) {
if (first) first = false;
else outbuf << ",";
print_json_tuple(conn, outbuf, it->key(), it->value());
outbuf.seekp(0);
}
mg_printf(conn, "]}\r\n");
delete it;
}
const boost::regex web_handle_api_range_size_R(
"/api/range/([a-zA-Z0-9\\.]+)/([0-9]+)/([0-9]+)/([0-9]+)");
void web_handle_api_range_size(const boost::cmatch &match, struct mg_connection *conn) {
std::string sensor(match[1].str());
uint64_t start = std::stoul(match[2].str());
uint64_t end = std::stoul(match[3].str());
uint64_t size = std::stoul(match[4].str());
leveldb::DB *db = getDB(sensor);
if (db == nullptr) {
mg_printf(conn, "HTTP/1.1 500 Internal Error\r\n"
"\r\n");
return;
}
mg_printf(conn,
"HTTP/1.1 200 OK\r\n"
"Content-Type: application/json\r\n"
"\r\n");
uint64_t step = std::max((uint64_t)1, (end-start) / size);
std::ostringstream out;
out << "{\"sensor\":\"" << sensor << "\", "
<< "\"error\":null, "
<< "\"size\":" << size << ", "
<< "\"step\":" << step << ", "
<< "\"data\":[";
mg_write(conn, out.str().c_str(), out.str().size());
bool first = true;
uint64_t actual_size = 0;
std::ostringstream outbuf;
leveldb::Iterator* it = db->NewIterator(leveldb::ReadOptions());
for (uint64_t key = start; key <= end; key += step) {
it->Seek(make_key(key));
if (!it->Valid()) continue;
if (first) first = false;
else outbuf << ",";
print_json_tuple(conn, outbuf, it->key(), it->value());
outbuf.seekp(0);
actual_size++;
}
mg_printf(conn, "], \"actual_size\":%ld}\r\n", actual_size);
delete it;
}
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