/usr/include/osmium/storage/byid/mmap_file.hpp is in libosmium-dev 0.0~20140910-9a069af-1+b1.
This file is owned by root:root, with mode 0o644.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 | #ifndef OSMIUM_STORAGE_BYID_MMAP_FILE_HPP
#define OSMIUM_STORAGE_BYID_MMAP_FILE_HPP
/*
Copyright 2012 Jochen Topf <jochen@topf.org> and others (see README).
This file is part of Osmium (https://github.com/joto/osmium).
Osmium is free software: you can redistribute it and/or modify it under the
terms of the GNU Lesser General Public License or (at your option) the GNU
General Public License as published by the Free Software Foundation, either
version 3 of the Licenses, or (at your option) any later version.
Osmium is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE. See the GNU Lesser General Public License and the GNU
General Public License for more details.
You should have received a copy of the Licenses along with Osmium. If not, see
<http://www.gnu.org/licenses/>.
*/
#include <cstdio>
#include <cstdlib>
#include <fcntl.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include <string>
#include <osmium/storage/byid.hpp>
namespace Osmium {
namespace Storage {
namespace ById {
/**
* MmapFile stores data in files using the mmap() system call.
* It will grow automatically.
*
* If you have enough memory it is preferred to use the in-memory
* version MmapAnon. If you don't have enough memory or want the
* data to persist, use this version. Note that in any case you need
* substantial amounts of memory for this to work efficiently.
*/
template <typename TValue>
class MmapFile : public Osmium::Storage::ById::Base<TValue> {
public:
static const uint64_t size_increment = 10 * 1024 * 1024;
/**
* Create mapping backed by file. If filename is empty, a temporary
* file will be created.
*
* @param filename The filename (including the path) for the storage.
* @param remove Should the file be removed after use?
* @exception std::bad_alloc Thrown when there is not enough memory or some other problem.
*/
MmapFile(const std::string& filename="", bool remove=true) :
Base<TValue>(),
m_size(1) {
if (filename == "") {
FILE* file = tmpfile();
if (!file) {
throw std::bad_alloc();
}
m_fd = fileno(file);
} else {
m_fd = open(filename.c_str(), O_RDWR | O_CREAT, 0600);
}
if (m_fd < 0) {
throw std::bad_alloc();
}
// now that the file is open we can immediately remove it
// (temporary files are always removed)
if (remove && filename != "") {
if (unlink(filename.c_str()) < 0) {
// XXX what to do here?
}
}
// make sure the file is at least as large as the initial size
if (get_file_size() < sizeof(TValue) * m_size) {
if (ftruncate(m_fd, sizeof(TValue) * m_size) < 0) {
throw std::bad_alloc();
}
}
m_items = static_cast<TValue*>(mmap(NULL, sizeof(TValue) * m_size, PROT_READ | PROT_WRITE, MAP_SHARED, m_fd, 0));
if (m_items == MAP_FAILED) {
throw std::bad_alloc();
}
}
~MmapFile() {
clear();
}
void set(const uint64_t id, const TValue value) {
if (id >= m_size) {
uint64_t new_size = id + size_increment;
// if the file backing this mmap is smaller than needed, increase its size
if (get_file_size() < sizeof(TValue) * new_size) {
if (ftruncate(m_fd, sizeof(TValue) * new_size) < 0) {
throw std::bad_alloc();
}
}
if (munmap(m_items, sizeof(TValue) * m_size) < 0) {
throw std::bad_alloc();
}
m_items = static_cast<TValue*>(mmap(NULL, sizeof(TValue) * new_size, PROT_READ | PROT_WRITE, MAP_SHARED, m_fd, 0));
if (m_items == MAP_FAILED) {
throw std::bad_alloc();
}
m_size = new_size;
}
m_items[id] = value;
}
const TValue operator[](const uint64_t id) const {
return m_items[id];
}
uint64_t size() const {
return m_size;
}
uint64_t used_memory() const {
return m_size * sizeof(TValue);
}
void clear() {
munmap(m_items, sizeof(TValue) * m_size);
}
private:
uint64_t m_size;
TValue* m_items;
int m_fd;
/// Get file size in bytes.
uint64_t get_file_size() const {
struct stat s;
if (fstat(m_fd, &s) < 0) {
throw std::bad_alloc();
}
return s.st_size;
}
}; // class MmapFile
} // namespace ById
} // namespace Storage
} // namespace Osmium
#endif // OSMIUM_STORAGE_BYID_MMAP_FILE_HPP
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