#!/bin/sh

# Exercises the cache. The first three tests set cache-size to nothing, one
# slot and the full table in turn, then count what the requests left behind.
# The rest cover a page longer than the output buffer and a key too long to
# be read back.

test_description='Validate cache'
. ./setup.sh

# The three counting tests below visit the same pages, the index plus six
# pages in each of two repositories, so the counts they expect stay tied to
# this one list of thirteen requests.
request_all_pages() {
	cgit_url "" &&
	for repo in foo bar
	do
		for page in "" /refs /tree /log /diff /patch
		do
			cgit_url "$repo$page" || return 1
		done
	done
}

set_cache_size() {
	sed -e "s/^cache-size=.*$/cache-size=$1/" cgitrc >cgitrc.tmp &&
	mv -f cgitrc.tmp cgitrc
}

test_expect_success 'verify cache-size=0' '
	rm -f cache/* &&
	set_cache_size 0 &&
	request_all_pages &&
	ls cache >output &&
	test_line_count = 0 output
'

test_expect_success 'verify cache-size=1' '
	rm -f cache/* &&
	set_cache_size 1 &&
	request_all_pages &&
	ls cache >output &&
	test_line_count = 1 output
'

test_expect_success 'verify cache-size=1021' '
	rm -f cache/* &&
	set_cache_size 1021 &&
	request_all_pages &&
	ls cache >output &&
	test_line_count = 13 output &&
	cgit_url "foo/ls_cache" >output.full &&
	strip_headers <output.full >output &&
	test_line_count = 13 output &&
	cgit_url "foo/ls_cache" >output.second &&
	test_cmp output.full output.second
'

# Page output is buffered, so a slot only holds the whole page if the buffer is
# emptied before the size of what was generated is taken. The blob set up here
# is larger than one buffer, so a missing flush would leave the cached copy cut
# short.
test_expect_success 'set up a repo with a page larger than the output buffer' '
	mkrepo repos/bigpage 1 &&
	(
		cd repos/bigpage &&
		awk "BEGIN{for(i=0;i<20000;i++) print \"line \" i \" of the big file\"}" >big.txt &&
		git add big.txt &&
		git commit -m "add big.txt"
	) &&
	{
		echo "virtual-root=/" &&
		echo "cache-root=$PWD/cache2" &&
		echo "cache-size=64" &&
		echo "enable-tree-linenumbers=1" &&
		echo "repo.url=bigpage" &&
		echo "repo.path=$PWD/repos/bigpage/.git"
	} >bigrc &&
	rm -rf cache2 && mkdir cache2
'

bigpage_query() {
	CGIT_CONFIG="$PWD/bigrc" QUERY_STRING="$1" cgit
}

test_expect_success 'the first request fills the slot and the second replays it' '
	bigpage_query "url=bigpage/tree/big.txt" >big.first &&
	test $(wc -c <big.first) -gt 65536 &&
	bigpage_query "url=bigpage/tree/big.txt" >big.second &&
	strip_headers <big.first >big.first.body &&
	strip_headers <big.second >big.second.body &&
	test_cmp big.first.body big.second.body
'

test_expect_success 'the cached body matches one generated with the cache off' '
	sed -e "s/^cache-size=64$/cache-size=0/" bigrc >bignocache &&
	CGIT_CONFIG="$PWD/bignocache" QUERY_STRING="url=bigpage/tree/big.txt" cgit >big.nocache &&
	strip_headers <big.nocache >big.nocache.body &&
	# The footer carries the time the page was generated, which the two runs
	# cannot agree on.
	sed -e "s/generated by .*//" big.nocache.body >big.nocache.timeless &&
	sed -e "s/generated by .*//" big.second.body >big.cached.timeless &&
	test_cmp big.nocache.timeless big.cached.timeless
'

test_expect_success 'the page ends where it should, so nothing was dropped' '
	tail -c 200 big.second.body | grep "</html>"
'

# A slot stores its key ahead of the content and only the first few kilobytes of
# it are read back, so a key longer than that could never match. A request
# carrying one used to leave a slot behind on every visit that nothing could
# ever go on to use.
test_expect_success 'an over-long cache key leaves no slot behind' '
	rm -rf cache3 && mkdir cache3 &&
	sed -e "s|^cache-root=.*|cache-root=$PWD/cache3|" bigrc >bigkeyrc &&
	long=$(awk "BEGIN{s=\"\";for(i=0;i<6000;i++)s=s \"k\"; print s}") &&
	CGIT_CONFIG="$PWD/bigkeyrc" QUERY_STRING="url=bigpage/&q=$long" cgit >key.out 2>key.err &&
	grep "</html>" key.out &&
	ls cache3 >key.slots &&
	test_line_count = 0 key.slots
'

test_expect_success 'an ordinary key still fills a slot' '
	rm -rf cache3 && mkdir cache3 &&
	CGIT_CONFIG="$PWD/bigkeyrc" QUERY_STRING="url=bigpage/" cgit >/dev/null &&
	ls cache3 >key.slots &&
	test_line_count = 1 key.slots
'

# An error page fired after rendering began abandons the fill with part of
# the page already written into the lock file. That fragment must be
# discarded along with the file, not replayed to the visitor behind the
# error page. A commit whose parent object is missing renders its whole
# info table before the diff machinery fails, which makes it the trigger.
test_expect_success 'set up a repo missing a parent object' '
	mkrepo repos/broken 2 &&
	parent=$(git -C repos/broken rev-parse HEAD^) &&
	tip=$(git -C repos/broken rev-parse HEAD) &&
	rm "repos/broken/.git/objects/$(echo "$parent" | cut -c1-2)/$(echo "$parent" | cut -c3-)" &&
	{
		echo "virtual-root=/" &&
		echo "cache-root=$PWD/cache4" &&
		echo "cache-size=64" &&
		echo "repo.url=broken" &&
		echo "repo.path=$PWD/repos/broken/.git"
	} >brokenrc &&
	rm -rf cache4 && mkdir cache4
'

test_expect_success 'an error after output began ends the page with it and caches nothing' '
	CGIT_CONFIG="$PWD/brokenrc" QUERY_STRING="url=broken/commit/&id=$tip" cgit >broken.out &&
	grep "Not a commit" broken.out &&
	test $(grep -c "^Status:" broken.out) = 1 &&
	ls cache4 >broken.slots &&
	test_line_count = 0 broken.slots
'

# An error page reports a condition the repository may grow out of, and a
# request pinned to an object id would cache it under the never-expiring
# static ttl. Asking for a commit that does not exist yet must therefore
# leave nothing behind, or the real page could never appear once it does.
test_expect_success 'an error page leaves no slot behind' '
	rm -rf cache3 && mkdir cache3 &&
	CGIT_CONFIG="$PWD/bigkeyrc" \
	QUERY_STRING="url=bigpage/commit/&id=0123456789abcdef0123456789abcdef01234567" cgit >error.out &&
	grep "Not a commit" error.out &&
	ls cache3 >error.slots &&
	test_line_count = 0 error.slots
'

# The dumb transport serves files that already sit on the disk, so a copy in
# a slot would only double the disk they take.
test_expect_success 'a clone file leaves no slot behind' '
	rm -rf cache3 && mkdir cache3 &&
	CGIT_CONFIG="$PWD/bigkeyrc" QUERY_STRING="url=bigpage/info/refs" cgit >clone.out &&
	grep "refs/heads/master" clone.out &&
	CGIT_CONFIG="$PWD/bigkeyrc" QUERY_STRING="url=bigpage/objects/info/packs" cgit >packs.out &&
	grep "^Status: 200" packs.out &&
	ls cache3 >clone.slots &&
	test_line_count = 0 clone.slots
'

# A response past cache-max-slot-size is served whole but kept nowhere, both
# on a first fill and when it would have replaced an expired slot, which is
# dropped along with it. The summary page stays under the limit set here
# while the big blob page is well past it.
test_expect_success 'a response over cache-max-slot-size is served but not kept' '
	rm -rf cache3 && mkdir cache3 &&
	{
		echo "cache-max-slot-size=32" &&
		cat bigkeyrc
	} >slotsizerc &&
	CGIT_CONFIG="$PWD/slotsizerc" QUERY_STRING="url=bigpage/tree/big.txt" cgit >big.unkept &&
	tail -c 200 big.unkept | grep "</html>" &&
	ls cache3 >unkept.slots &&
	test_line_count = 0 unkept.slots &&
	CGIT_CONFIG="$PWD/slotsizerc" QUERY_STRING="url=bigpage/" cgit >/dev/null &&
	ls cache3 >kept.slots &&
	test_line_count = 1 kept.slots
'

test_expect_success 'an expired slot is dropped when its refill is too large' '
	rm -rf cache3 && mkdir cache3 &&
	CGIT_CONFIG="$PWD/bigkeyrc" QUERY_STRING="url=bigpage/tree/big.txt" cgit >/dev/null &&
	ls cache3 >filled.slots &&
	test_line_count = 1 filled.slots &&
	touch -t 200001010000 cache3/* &&
	CGIT_CONFIG="$PWD/slotsizerc" QUERY_STRING="url=bigpage/tree/big.txt" cgit >big.refill &&
	tail -c 200 big.refill | grep "</html>" &&
	ls cache3 >refill.slots &&
	test_line_count = 0 refill.slots
'

test_done