[7] | 1 | |
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| 2 | /* |
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| 3 | Copyright 2013 Willem Vermin, SURFsara |
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| 4 | |
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| 5 | Licensed under the Apache License, Version 2.0 (the "License"); |
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| 6 | you may not use this file except in compliance with the License. |
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| 7 | You may obtain a copy of the License at |
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| 8 | |
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| 9 | http://www.apache.org/licenses/LICENSE-2.0 |
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| 10 | |
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| 11 | Unless required by applicable law or agreed to in writing, software |
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| 12 | distributed under the License is distributed on an "AS IS" BASIS, |
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| 13 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
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| 14 | See the License for the specific language governing permissions and |
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| 15 | limitations under the License. |
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| 16 | */ |
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| 17 | #include "stopos_pool.h" |
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| 18 | #include "flatfile_pool.h" |
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| 19 | #include <sys/types.h> |
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| 20 | #include <sys/stat.h> |
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| 21 | #include <errno.h> |
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| 22 | #include <fcntl.h> |
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| 23 | #include <stdlib.h> |
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| 24 | #include "wutils.h" |
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| 25 | #include <string.h> |
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| 26 | #include <strings.h> |
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| 27 | #include <stdio.h> |
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| 28 | #include <algorithm> |
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| 29 | #include "stopos.h" |
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| 30 | |
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| 31 | // |
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| 32 | // this->status.extra is always pointing to |
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| 33 | // the first free slot |
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| 34 | // |
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| 35 | // records are stored thusly: |
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| 36 | // character to denote if this record exists or is deleted |
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| 37 | // dbsep |
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| 38 | // |
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| 39 | // for a not deleted record, next fields: |
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| 40 | // key for this record |
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| 41 | // dbsep |
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| 42 | // 1st parameter of put_record |
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| 43 | // |
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| 44 | // for a deleted record: |
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| 45 | // pointer to next deleted record |
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| 46 | // |
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| 47 | |
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| 48 | // constructor |
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| 49 | flatfile_pool::flatfile_pool() |
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| 50 | { |
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| 51 | this->whoami = "flat"; |
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| 52 | this->statuskey.set_slot(this->statuskey.get_key()); |
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| 53 | } |
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| 54 | |
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| 55 | std::string flatfile_pool::key_to_slot(const std::string &k) |
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| 56 | { |
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| 57 | |
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| 58 | if (strtoslot(this->status.extra) == 0) |
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| 59 | return k; |
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| 60 | |
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| 61 | std::string slot = this->status.extra; |
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| 62 | std::string r; |
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| 63 | off_t p = strtoslot(slot)*this->reclen; |
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| 64 | this->read_string(r, p); |
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| 65 | this->status.extra = r.substr(2); |
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| 66 | |
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| 67 | return slot; |
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| 68 | } |
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| 69 | |
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| 70 | off_t flatfile_pool::strtoslot(const std::string &s) |
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| 71 | { |
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| 72 | return stopos_key::KeyToNumber(s); |
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| 73 | } |
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| 74 | |
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| 75 | std::string flatfile_pool::slottostr(off_t l) |
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| 76 | { |
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| 77 | return stopos_key::NumberToKey(l); |
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| 78 | } |
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| 79 | |
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| 80 | int flatfile_pool::haskey(std::string &r, const std::string &k) |
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| 81 | { |
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| 82 | size_t q1 = 1; |
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| 83 | // find second separator. The first one is on postion 1 |
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| 84 | size_t q2 = r.find(dbsep,2); |
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| 85 | |
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| 86 | std::string key = r.substr(q1+1,q2-q1-1); |
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| 87 | if (key != k) |
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| 88 | return this->NOTFOUND; |
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| 89 | r.erase(0,q2+1); |
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| 90 | return 0; |
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| 91 | } |
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| 92 | |
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| 93 | int flatfile_pool::get_record(std::string &r, const std::string &k, const std::string &l) |
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| 94 | { |
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| 95 | int rc; |
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| 96 | |
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| 97 | off_t p = this->strtoslot(l)*reclen; |
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| 98 | |
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| 99 | rc = this->read_string(r,p); |
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| 100 | if (rc !=0 ) |
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| 101 | return rc; |
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| 102 | |
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| 103 | if (r[0] == this->deleted) |
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| 104 | return this->NOTFOUND; |
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| 105 | |
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| 106 | // this record was not deleted, but it could be that |
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| 107 | // the key does not match |
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| 108 | // |
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| 109 | |
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| 110 | rc = this->haskey(r,k); |
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| 111 | if (rc != 0) |
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| 112 | return rc; |
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| 113 | |
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| 114 | return 0; |
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| 115 | } |
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| 116 | |
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| 117 | int flatfile_pool::put_record(const std::string &r, |
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| 118 | const std::string &k, |
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| 119 | const std::string &l) |
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| 120 | { |
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| 121 | std::string buf; |
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| 122 | |
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| 123 | bool rectoolong = 0; |
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| 124 | |
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| 125 | buf = buf + this->exists + dbsep + k + dbsep + r; |
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| 126 | |
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| 127 | if (buf.size() >= this->reclen) // >= because we need place for |
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| 128 | // end-of-string zero |
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| 129 | { |
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| 130 | rectoolong = 1; |
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| 131 | buf.resize(reclen-1); |
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| 132 | } |
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| 133 | |
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| 134 | off_t p = this->strtoslot(l)*reclen; |
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| 135 | |
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| 136 | int rc = this->write_string(buf,p); |
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| 137 | if (!rectoolong) |
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| 138 | return rc; |
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| 139 | return RECORDTOOLONG; |
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| 140 | } |
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| 141 | |
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| 142 | int flatfile_pool::remove_record(const std::string &k, const std::string &l) |
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| 143 | { |
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| 144 | int rc; |
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| 145 | |
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| 146 | off_t p = this->strtoslot(l)*reclen; |
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| 147 | |
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| 148 | std::string r; |
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| 149 | rc = this->read_string(r,p); |
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| 150 | if (rc != 0) |
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| 151 | return rc; |
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| 152 | |
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| 153 | rc = haskey(r,k); |
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| 154 | if (rc != 0) |
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| 155 | return rc; |
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| 156 | |
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| 157 | r = this->deleted; |
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| 158 | |
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| 159 | if (status.extra == slottostr(0)) |
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| 160 | r = r + dbsep + slottostr(0); |
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| 161 | else |
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| 162 | r = r + dbsep + status.extra; |
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| 163 | status.extra = l; |
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| 164 | |
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| 165 | return this->write_string(r,p); |
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| 166 | } |
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| 167 | |
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| 168 | int flatfile_pool::read_string(std::string &r, off_t p) |
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| 169 | { |
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| 170 | |
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| 171 | char b[this->reclen]; |
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| 172 | off_t rc; |
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| 173 | rc = lseek(this->ff, p, SEEK_SET); |
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| 174 | if (rc == -1) |
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| 175 | return FETCHERROR; |
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| 176 | |
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| 177 | ssize_t rc1; |
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| 178 | rc1 = read(this->ff, b, this->reclen); |
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| 179 | if (rc1 != this->reclen) |
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| 180 | return FETCHERROR; |
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| 181 | |
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| 182 | r = b; |
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| 183 | |
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| 184 | return 0; |
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| 185 | } |
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| 186 | |
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| 187 | |
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| 188 | int flatfile_pool::write_string(const std::string &r, off_t p) |
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| 189 | { |
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| 190 | int rc; |
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| 191 | char b[this->reclen]; |
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| 192 | |
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| 193 | rc = lseek(this->ff,p,SEEK_SET); |
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| 194 | if (rc == -1) |
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| 195 | return STOREERROR; |
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| 196 | |
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| 197 | bzero(b, this->reclen); |
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| 198 | strncpy(b,r.c_str(),r.size()); |
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| 199 | ssize_t first = 0; |
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| 200 | ssize_t togo = this->reclen; |
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| 201 | ssize_t written; |
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| 202 | |
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| 203 | do |
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| 204 | { |
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| 205 | written = write(ff,&b[first],togo); |
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| 206 | if (written == -1) |
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| 207 | { |
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| 208 | perror("write:"); |
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| 209 | return 2; |
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| 210 | } |
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| 211 | togo -= written; |
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| 212 | first += written; |
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| 213 | } while(togo !=0); |
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| 214 | |
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| 215 | return 0; |
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| 216 | } |
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| 217 | |
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| 218 | |
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| 219 | int flatfile_pool::create_db(const std::string &dbname) |
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| 220 | { |
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| 221 | int rc; |
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| 222 | |
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| 223 | rc = this->purge_db(); |
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| 224 | if (rc != 0) |
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| 225 | return rc; |
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| 226 | |
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| 227 | // The db_name can be composed of parts separated with '/' |
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| 228 | // we try to create this path until the last '/' |
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| 229 | |
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| 230 | size_t p = dbname.find_last_of('/'); |
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| 231 | rc = mkdir_p(dbname.substr(0,p+1),0755); |
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| 232 | if (rc != 0) |
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| 233 | return CREATEERROR; |
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| 234 | |
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| 235 | rc = this->open_db(O_CREAT|O_RDWR); |
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| 236 | if (rc != 0) |
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| 237 | return rc; |
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| 238 | this->close_db(); |
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| 239 | |
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| 240 | this->status.extra = stopos_key::NumberToKey(0); |
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| 241 | |
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| 242 | return 0; |
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| 243 | } |
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| 244 | |
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| 245 | int flatfile_pool::purge_db(void) |
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| 246 | { |
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| 247 | if (this->db_name == 0) |
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| 248 | return NOFILENAME; |
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| 249 | |
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| 250 | this->close_db(); |
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| 251 | |
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| 252 | unlink(this->db_name); |
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| 253 | return 0; |
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| 254 | } |
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| 255 | |
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| 256 | int flatfile_pool::open_db() |
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| 257 | { |
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| 258 | int rc; |
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| 259 | rc = this->open_db(O_RDWR); |
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| 260 | return rc; |
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| 261 | } |
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| 262 | |
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| 263 | int flatfile_pool::open_db(int flags) |
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| 264 | { |
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| 265 | int rc; |
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| 266 | |
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| 267 | if (this->db_name == 0) |
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| 268 | return NOFILENAME; |
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| 269 | |
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| 270 | if (this->db_open) |
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| 271 | return 0; |
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| 272 | |
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| 273 | this->ff = open(this->db_name, flags,0644); |
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| 274 | if (this->ff < 0) |
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| 275 | return OPENERROR; |
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| 276 | |
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| 277 | struct flock lock; |
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| 278 | lock.l_type = F_RDLCK|F_WRLCK; |
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| 279 | lock.l_whence = SEEK_SET; |
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| 280 | lock.l_start = 0; |
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| 281 | lock.l_len = 0; |
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| 282 | |
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| 283 | rc = fcntl(this->ff,F_SETLKW,&lock); |
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| 284 | if (rc < 0) |
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| 285 | return LOCKERROR; |
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| 286 | |
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| 287 | this->db_open = 1; |
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| 288 | |
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| 289 | return 0; |
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| 290 | } |
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| 291 | |
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| 292 | int flatfile_pool::close_db(void) |
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| 293 | { |
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| 294 | if (!this->db_open) |
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| 295 | return 0; |
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| 296 | |
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| 297 | int rc; |
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| 298 | |
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| 299 | struct flock lock; |
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| 300 | lock.l_type = F_UNLCK; |
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| 301 | lock.l_whence = SEEK_SET; |
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| 302 | lock.l_start = 0; |
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| 303 | lock.l_len = 0; |
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| 304 | |
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| 305 | rc = fcntl(this->ff,F_SETLKW,&lock); |
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| 306 | if (rc < 0) |
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| 307 | return UNLOCKERROR; |
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| 308 | |
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| 309 | rc = close(this->ff); |
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| 310 | if (rc == -1) |
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| 311 | return CLOSEERROR; |
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| 312 | |
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| 313 | this->db_open = 0; |
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| 314 | |
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| 315 | return 0; |
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| 316 | } |
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| 317 | |
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