// Copyright (c) 2016 Sandstorm Development Group, Inc. and contributors // Licensed under the MIT License: // // Permission is hereby granted, free of charge, to any person obtaining a copy // of this software and associated documentation files (the "Software"), to deal // in the Software without restriction, including without limitation the rights // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell // copies of the Software, and to permit persons to whom the Software is // furnished to do so, subject to the following conditions: // // The above copyright notice and this permission notice shall be included in // all copies or substantial portions of the Software. // // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN // THE SOFTWARE. #include "readiness-io.h" namespace kj { static size_t copyInto(kj::ArrayPtr<byte> dst, kj::ArrayPtr<const byte>& src) { size_t n = kj::min(dst.size(), src.size()); memcpy(dst.begin(), src.begin(), n); src = src.slice(n, src.size()); return n; } // ======================================================================================= ReadyInputStreamWrapper::ReadyInputStreamWrapper(AsyncInputStream& input): input(input) {} ReadyInputStreamWrapper::~ReadyInputStreamWrapper() noexcept(false) {} kj::Maybe<size_t> ReadyInputStreamWrapper::read(kj::ArrayPtr<byte> dst) { if (eof || dst.size() == 0) return size_t(0); if (content.size() == 0) { // No data available. Try to read more. if (!isPumping) { isPumping = true; pumpTask = kj::evalNow([&]() { return input.tryRead(buffer, 1, sizeof(buffer)).then([this](size_t n) { if (n == 0) { eof = true; } else { content = kj::arrayPtr(buffer, n); } isPumping = false; }); }).fork(); } return nullptr; } return copyInto(dst, content); } kj::Promise<void> ReadyInputStreamWrapper::whenReady() { return pumpTask.addBranch(); } // ======================================================================================= ReadyOutputStreamWrapper::ReadyOutputStreamWrapper(AsyncOutputStream& output): output(output) {} ReadyOutputStreamWrapper::~ReadyOutputStreamWrapper() noexcept(false) {} kj::Maybe<size_t> ReadyOutputStreamWrapper::write(kj::ArrayPtr<const byte> data) { if (data.size() == 0) return size_t(0); if (filled == sizeof(buffer)) { // No space. return nullptr; } uint end = start + filled; size_t result = 0; if (end < sizeof(buffer)) { // The filled part of the buffer is somewhere in the middle. // Copy into space after filled space. result += copyInto(kj::arrayPtr(buffer + end, buffer + sizeof(buffer)), data); // Copy into space before filled space. result += copyInto(kj::arrayPtr(buffer, buffer + start), data); } else { // Fill currently loops, so we only have one segment of empty space to copy into. // Copy into the space between the fill's end and the fill's start. result += copyInto(kj::arrayPtr(buffer + end % sizeof(buffer), buffer + start), data); } filled += result; if (!isPumping) { isPumping = true; pumpTask = kj::evalNow([&]() { return pump(); }).fork(); } return result; } kj::Promise<void> ReadyOutputStreamWrapper::whenReady() { return pumpTask.addBranch(); } kj::Promise<void> ReadyOutputStreamWrapper::pump() { uint oldFilled = filled; uint end = start + filled; kj::Promise<void> promise = nullptr; if (end <= sizeof(buffer)) { promise = output.write(buffer + start, filled); } else { end = end % sizeof(buffer); segments[0] = kj::arrayPtr(buffer + start, buffer + sizeof(buffer)); segments[1] = kj::arrayPtr(buffer, buffer + end); promise = output.write(segments); } return promise.then([this,oldFilled,end]() -> kj::Promise<void> { filled -= oldFilled; start = end; if (filled > 0) { return pump(); } else { isPumping = false; return kj::READY_NOW; } }); } } // namespace kj