forked from premiere/premiere-libtorrent
244 lines
6.4 KiB
C++
244 lines
6.4 KiB
C++
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/*
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Copyright (c) 2008, Arvid Norberg
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All rights reserved.
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions
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are met:
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* Redistributions of source code must retain the above copyright
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notice, this list of conditions and the following disclaimer.
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* Redistributions in binary form must reproduce the above copyright
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notice, this list of conditions and the following disclaimer in
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the documentation and/or other materials provided with the distribution.
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* Neither the name of the author nor the names of its
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contributors may be used to endorse or promote products derived
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from this software without specific prior written permission.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
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LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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POSSIBILITY OF SUCH DAMAGE.
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*/
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#include "libtorrent/lazy_entry.hpp"
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namespace libtorrent
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{
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int fail_bdecode() { return -1; }
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// fills in 'val' with what the string between start and the
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// first occurance of the delimiter is interpreted as an int.
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// return the pointer to the delimiter, or 0 if there is a
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// parse error. val should be initialized to zero
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char* parse_int(char* start, char* end, char delimiter, boost::int64_t& val)
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{
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while (start < end && *start != delimiter)
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{
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if (!std::isdigit(*start)) { fail_bdecode(); return 0; }
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val *= 10;
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val += *start - '0';
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++start;
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}
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return start;
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}
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char* find_char(char* start, char* end, char delimiter)
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{
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while (start < end && *start != delimiter) ++start;
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return start;
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}
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// return 0 = success
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int lazy_bdecode(char* start, char* end, lazy_entry& ret, int depth_limit)
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{
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ret.clear();
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if (start == end) return 0;
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std::vector<lazy_entry*> stack;
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stack.push_back(&ret);
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while (start < end)
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{
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if (stack.empty()) break; // done!
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lazy_entry* top = stack.back();
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if (stack.size() > depth_limit) return fail_bdecode();
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if (start == end) return fail_bdecode();
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char t = *start;
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*start = 0; // null terminate any previous string
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++start;
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if (start == end && t != 'e') return fail_bdecode();
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switch (top->type())
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{
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case lazy_entry::dict_t:
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{
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if (t == 'e')
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{
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stack.pop_back();
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continue;
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}
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boost::int64_t len = t - '0';
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start = parse_int(start, end, ':', len);
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if (start == 0 || start + len + 3 > end || *start != ':') return fail_bdecode();
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++start;
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lazy_entry* ent = top->dict_append(start);
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start += len;
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stack.push_back(ent);
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t = *start;
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*start = 0; // null terminate any previous string
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++start;
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break;
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}
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case lazy_entry::list_t:
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{
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if (t == 'e')
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{
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stack.pop_back();
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continue;
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}
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lazy_entry* ent = top->list_append();
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stack.push_back(ent);
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break;
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}
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default: break;
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}
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top = stack.back();
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switch (t)
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{
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case 'd':
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top->construct_dict();
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continue;
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case 'l':
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top->construct_list();
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continue;
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case 'i':
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top->construct_int(start);
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start = find_char(start, end, 'e');
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if (start == end) return fail_bdecode();
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TORRENT_ASSERT(*start == 'e');
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*start++ = 0;
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stack.pop_back();
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continue;
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default:
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{
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if (!std::isdigit(t)) return fail_bdecode();
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boost::int64_t len = t - '0';
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start = parse_int(start, end, ':', len);
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if (start == 0 || start + len + 1 > end || *start != ':') return fail_bdecode();
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++start;
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top->construct_string(start);
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stack.pop_back();
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start += len;
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continue;
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}
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}
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return 0;
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}
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return 0;
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}
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boost::int64_t lazy_entry::int_value() const
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{
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TORRENT_ASSERT(m_type == int_t);
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boost::int64_t val = 0;
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bool negative = false;
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if (*m_data.start == '-') negative = true;
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parse_int(negative?m_data.start+1:m_data.start, m_data.start + 100, 0, val);
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if (negative) val = -val;
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return val;
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}
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lazy_entry* lazy_entry::dict_append(char* name)
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{
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TORRENT_ASSERT(m_type == dict_t);
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TORRENT_ASSERT(m_size <= m_capacity);
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if (m_capacity == 0)
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{
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int capacity = 10;
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m_data.dict = new (std::nothrow) std::pair<char*, lazy_entry>[capacity];
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if (m_data.dict == 0) return 0;
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m_capacity = capacity;
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}
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else if (m_size == m_capacity)
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{
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int capacity = m_capacity * 2;
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std::pair<char*, lazy_entry>* tmp = new (std::nothrow) std::pair<char*, lazy_entry>[capacity];
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if (tmp == 0) return 0;
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std::memcpy(tmp, m_data.dict, sizeof(std::pair<char*, lazy_entry>) * m_size);
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delete[] m_data.dict;
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m_data.dict = tmp;
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m_capacity = capacity;
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}
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TORRENT_ASSERT(m_size < m_capacity);
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std::pair<char*, lazy_entry>& ret = m_data.dict[m_size++];
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ret.first = name;
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return &ret.second;
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}
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lazy_entry* lazy_entry::dict_find(char const* name)
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{
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TORRENT_ASSERT(m_type == dict_t);
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for (int i = 0; i < m_size; ++i)
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{
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if (strcmp(name, m_data.dict[i].first) == 0)
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return &m_data.dict[i].second;
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}
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return 0;
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}
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lazy_entry* lazy_entry::list_append()
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{
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TORRENT_ASSERT(m_type == list_t);
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TORRENT_ASSERT(m_size <= m_capacity);
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if (m_capacity == 0)
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{
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int capacity = 10;
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m_data.list = new (std::nothrow) lazy_entry[capacity];
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if (m_data.list == 0) return 0;
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m_capacity = capacity;
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}
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else if (m_size == m_capacity)
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{
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int capacity = m_capacity * 2;
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lazy_entry* tmp = new (std::nothrow) lazy_entry[capacity];
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if (tmp == 0) return 0;
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std::memcpy(tmp, m_data.list, sizeof(lazy_entry) * m_size);
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delete[] m_data.list;
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m_data.list = tmp;
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m_capacity = capacity;
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}
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TORRENT_ASSERT(m_size < m_capacity);
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return m_data.list + (m_size++);
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}
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void lazy_entry::clear()
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{
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switch (m_type)
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{
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case list_t: delete[] m_data.list; break;
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case dict_t: delete[] m_data.dict; break;
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default: break;
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}
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m_size = 0;
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m_capacity = 0;
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m_type = none_t;
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}
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};
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