nghttp2/src/shrpx_router.cc

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/*
* nghttp2 - HTTP/2 C Library
*
* Copyright (c) 2015 Tatsuhiro Tsujikawa
*
* 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 "shrpx_router.h"
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#include <algorithm>
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#include "shrpx_config.h"
namespace shrpx {
RNode::RNode() : s(nullptr), len(0), index(-1) {}
RNode::RNode(const char *s, size_t len, size_t index)
: s(s), len(len), index(index) {}
Router::Router() : root_{} {}
namespace {
RNode *find_next_node(const RNode *node, char c) {
auto itr = std::lower_bound(std::begin(node->next), std::end(node->next), c,
[](const std::unique_ptr<RNode> &lhs,
const char c) { return lhs->s[0] < c; });
if (itr == std::end(node->next) || (*itr)->s[0] != c) {
return nullptr;
}
return (*itr).get();
}
} // namespace
namespace {
void add_next_node(RNode *node, std::unique_ptr<RNode> new_node) {
auto itr = std::lower_bound(std::begin(node->next), std::end(node->next),
new_node->s[0],
[](const std::unique_ptr<RNode> &lhs,
const char c) { return lhs->s[0] < c; });
node->next.insert(itr, std::move(new_node));
}
} // namespace
void Router::add_node(RNode *node, const char *pattern, size_t patlen,
size_t index) {
auto new_node = make_unique<RNode>(pattern, patlen, index);
add_next_node(node, std::move(new_node));
}
bool Router::add_route(const StringRef &pattern, size_t index) {
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auto node = &root_;
size_t i = 0;
for (;;) {
auto next_node = find_next_node(node, pattern[i]);
if (next_node == nullptr) {
add_node(node, pattern.c_str() + i, pattern.size() - i, index);
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return true;
}
node = next_node;
auto slen = pattern.size() - i;
auto s = pattern.c_str() + i;
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auto n = std::min(node->len, slen);
size_t j;
for (j = 0; j < n && node->s[j] == s[j]; ++j)
;
if (j == n) {
// The common prefix was matched
if (slen == node->len) {
// Complete match
if (node->index != -1) {
// Don't allow duplicate
return false;
}
node->index = index;
return true;
}
if (slen > node->len) {
// We still have pattern to add
i += j;
continue;
}
}
if (node->len > j) {
// node must be split into 2 nodes. new_node is now the child
// of node.
auto new_node =
make_unique<RNode>(&node->s[j], node->len - j, node->index);
std::swap(node->next, new_node->next);
node->len = j;
node->index = -1;
add_next_node(node, std::move(new_node));
if (slen == j) {
node->index = index;
return true;
}
}
i += j;
assert(pattern.size() > i);
add_node(node, pattern.c_str() + i, pattern.size() - i, index);
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return true;
}
}
namespace {
const RNode *match_complete(size_t *offset, const RNode *node,
const char *first, const char *last) {
*offset = 0;
if (first == last) {
return node;
}
auto p = first;
for (;;) {
auto next_node = find_next_node(node, *p);
if (next_node == nullptr) {
return nullptr;
}
node = next_node;
auto n = std::min(node->len, static_cast<size_t>(last - p));
if (memcmp(node->s, p, n) != 0) {
return nullptr;
}
p += n;
if (p == last) {
*offset = n;
return node;
}
}
}
} // namespace
namespace {
const RNode *match_partial(const RNode *node, size_t offset, const char *first,
const char *last) {
if (first == last) {
if (node->len == offset) {
return node;
}
return nullptr;
}
auto p = first;
const RNode *found_node = nullptr;
if (offset > 0) {
auto n = std::min(node->len - offset, static_cast<size_t>(last - first));
if (memcmp(node->s + offset, first, n) != 0) {
return nullptr;
}
p += n;
if (p == last) {
if (node->len == offset + n) {
if (node->index != -1) {
return node;
}
return nullptr;
}
if (node->index != -1 && offset + n + 1 == node->len &&
node->s[node->len - 1] == '/') {
return node;
}
return nullptr;
}
if (node->index != -1 && node->s[node->len - 1] == '/') {
found_node = node;
}
assert(node->len == offset + n);
}
for (;;) {
auto next_node = find_next_node(node, *p);
if (next_node == nullptr) {
return found_node;
}
node = next_node;
auto n = std::min(node->len, static_cast<size_t>(last - p));
if (memcmp(node->s, p, n) != 0) {
return found_node;
}
p += n;
if (p == last) {
if (node->len == n) {
// Complete match with this node
if (node->index != -1) {
return node;
}
return found_node;
}
// We allow match without trailing "/" at the end of pattern.
// So, if pattern ends with '/', and pattern and path matches
// without that slash, we consider they match to deal with
// request to the directory without trailing slash. That is if
// pattern is "/foo/" and path is "/foo", we consider they
// match.
if (node->index != -1 && n + 1 == node->len && node->s[n] == '/') {
return node;
}
return found_node;
}
// This is the case when pattern which ends with "/" is included
// in query.
if (node->index != -1 && node->s[node->len - 1] == '/') {
found_node = node;
}
assert(node->len == n);
}
}
} // namespace
ssize_t Router::match(const std::string &host, const char *path,
size_t pathlen) const {
const RNode *node;
size_t offset;
node =
match_complete(&offset, &root_, host.c_str(), host.c_str() + host.size());
if (node == nullptr) {
return -1;
}
node = match_partial(node, offset, path, path + pathlen);
if (node == nullptr || node == &root_) {
return -1;
}
return node->index;
}
namespace {
void dump_node(const RNode *node, int depth) {
fprintf(stderr, "%*ss='%.*s', len=%zu, index=%zd\n", depth, "",
(int)node->len, node->s, node->len, node->index);
for (auto &nd : node->next) {
dump_node(nd.get(), depth + 4);
}
}
} // namespace
void Router::dump() const { dump_node(&root_, 0); }
} // namespace shrpx