diff options
Diffstat (limited to 'src/shared_buffer.cc')
| -rw-r--r-- | src/shared_buffer.cc | 198 |
1 files changed, 198 insertions, 0 deletions
diff --git a/src/shared_buffer.cc b/src/shared_buffer.cc new file mode 100644 index 0000000..7ad168a --- /dev/null +++ b/src/shared_buffer.cc @@ -0,0 +1,198 @@ +/** + * Copyright (c) 2014, Timothy Stack + * + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * * Redistributions of source code must retain the above copyright notice, this + * list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * * Neither the name of Timothy Stack nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ''AS IS'' AND ANY + * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED + * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE + * DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY + * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; + * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND + * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * @file shared_buffer.cc + */ + +#include "config.h" + +#ifdef HAVE_EXECINFO_H +# include <execinfo.h> +#endif + +#include <algorithm> + +#include "base/ansi_scrubber.hh" +#include "shared_buffer.hh" + +static const bool DEBUG_TRACE = false; + +void +shared_buffer_ref::share(shared_buffer& sb, const char* data, size_t len) +{ +#ifdef HAVE_EXECINFO_H + if (DEBUG_TRACE) { + void* frames[128]; + int rc; + + rc = backtrace(frames, 128); + this->sb_backtrace.reset(backtrace_symbols(frames, rc)); + } +#endif + + this->disown(); + + sb.add_ref(*this); + this->sb_owner = &sb; + this->sb_data = data; + this->sb_length = len; + + ensure(this->sb_length < (10 * 1024 * 1024)); +} + +bool +shared_buffer_ref::subset(shared_buffer_ref& other, off_t offset, size_t len) +{ + this->disown(); + + if (offset != -1) { + this->sb_owner = other.sb_owner; + this->sb_length = len; + if (this->sb_owner == nullptr) { + if ((this->sb_data = (char*) malloc(this->sb_length)) == nullptr) { + return false; + } + + memcpy( + const_cast<char*>(this->sb_data), &other.sb_data[offset], len); + } else { + this->sb_owner->add_ref(*this); + this->sb_data = &other.sb_data[offset]; + } + } + return true; +} + +shared_buffer_ref::shared_buffer_ref(shared_buffer_ref&& other) noexcept +{ + if (other.sb_data == nullptr) { + this->sb_owner = nullptr; + this->sb_data = nullptr; + this->sb_length = 0; + } else if (other.sb_owner != nullptr) { + auto owner_ref_iter = std::find(other.sb_owner->sb_refs.begin(), + other.sb_owner->sb_refs.end(), + &other); + *owner_ref_iter = this; + this->sb_owner = std::exchange(other.sb_owner, nullptr); + this->sb_data = std::exchange(other.sb_data, nullptr); + this->sb_length = std::exchange(other.sb_length, 0); + } else { + this->sb_owner = nullptr; + this->sb_data = other.sb_data; + this->sb_length = other.sb_length; + other.sb_data = nullptr; + other.sb_length = 0; + } +} + +bool +shared_buffer_ref::take_ownership() +{ + if (this->sb_owner != nullptr && this->sb_data != nullptr) { + char* new_data; + + if ((new_data = (char*) malloc(this->sb_length)) == nullptr) { + return false; + } + + memcpy(new_data, this->sb_data, this->sb_length); + this->sb_data = new_data; + this->sb_owner->sb_refs.erase(find(this->sb_owner->sb_refs.begin(), + this->sb_owner->sb_refs.end(), + this)); + this->sb_owner = nullptr; + } + return true; +} + +void +shared_buffer_ref::disown() +{ + if (this->sb_owner == nullptr) { + if (this->sb_data != nullptr) { + free(const_cast<char*>(this->sb_data)); + } + } else { + this->sb_owner->sb_refs.erase(find(this->sb_owner->sb_refs.begin(), + this->sb_owner->sb_refs.end(), + this)); + } + this->sb_owner = nullptr; + this->sb_data = nullptr; + this->sb_length = 0; +} + +void +shared_buffer_ref::copy_ref(const shared_buffer_ref& other) +{ + if (other.sb_data == nullptr) { + this->sb_owner = nullptr; + this->sb_data = nullptr; + this->sb_length = 0; + } else if (other.sb_owner != nullptr) { + this->share(*other.sb_owner, other.sb_data, other.sb_length); + } else { + this->sb_owner = nullptr; + this->sb_data = (char*) malloc(other.sb_length); + memcpy( + const_cast<char*>(this->sb_data), other.sb_data, other.sb_length); + this->sb_length = other.sb_length; + } + this->sb_metadata = other.sb_metadata; +} + +shared_buffer_ref::narrow_result +shared_buffer_ref::narrow(size_t new_data, size_t new_length) +{ + return std::make_pair( + std::exchange(this->sb_data, this->sb_data + new_data), + std::exchange(this->sb_length, new_length)); +} + +void +shared_buffer_ref::widen(narrow_result old_data_length) +{ + this->sb_data = old_data_length.first; + this->sb_length = old_data_length.second; +} + +void +shared_buffer_ref::erase_ansi() +{ + if (!this->sb_metadata.m_has_ansi) { + return; + } + + auto* writable_data = this->get_writable_data(); + auto new_len = erase_ansi_escapes( + string_fragment::from_bytes(writable_data, this->sb_length)); + + this->sb_length = new_len; + this->sb_metadata.m_has_ansi = false; +} |