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resolve: drop support for old-style compressed BeesAddr

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No public version of bees ever created old-style compressed hash table
entries.  Remove the code that supports them.

Signed-off-by: Zygo Blaxell <bees@furryterror.org>
This commit is contained in:
Zygo Blaxell
2018-01-28 14:50:09 -05:00
parent 27125b8140
commit 591a44e59a
2 changed files with 53 additions and 69 deletions
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115
src/bees-resolve.cc
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@ -98,90 +98,77 @@ BeesResolver::adjust_offset(const BeesFileRange &haystack, const BeesBlockData &
return BeesBlockData();
}
off_t lower_offset = haystack.begin();
off_t upper_offset = haystack.end();
off_t haystack_offset = haystack.begin();
bool is_compressed_offset = false;
bool is_exact = false;
bool is_legacy = false;
if (m_addr.is_compressed()) {
BtrfsExtentWalker ew(haystack.fd(), haystack.begin(), m_ctx->root_fd());
BEESTRACE("haystack extent data " << ew);
Extent e = ew.current();
if (m_addr.has_compressed_offset()) {
off_t coff = m_addr.get_compressed_offset();
if (e.offset() > coff) {
// this extent begins after the target block
BEESCOUNT(adjust_offset_low);
return BeesBlockData();
}
coff -= e.offset();
if (e.size() <= coff) {
// this extent ends before the target block
BEESCOUNT(adjust_offset_high);
return BeesBlockData();
}
lower_offset = e.begin() + coff;
upper_offset = lower_offset + BLOCK_SIZE_CLONE;
BEESCOUNT(adjust_offset_hit);
is_compressed_offset = true;
} else {
lower_offset = e.begin();
upper_offset = e.end();
BEESCOUNT(adjust_legacy);
is_legacy = true;
THROW_CHECK1(runtime_error, m_addr, m_addr.has_compressed_offset());
off_t coff = m_addr.get_compressed_offset();
if (e.offset() > coff) {
// this extent begins after the target block
BEESCOUNT(adjust_offset_low);
return BeesBlockData();
}
coff -= e.offset();
if (e.size() <= coff) {
// this extent ends before the target block
BEESCOUNT(adjust_offset_high);
return BeesBlockData();
}
haystack_offset = e.begin() + coff;
BEESCOUNT(adjust_offset_hit);
is_compressed_offset = true;
} else {
BEESCOUNT(adjust_exact);
is_exact = true;
}
BEESTRACE("Checking haystack " << haystack << " offsets " << to_hex(lower_offset) << ".." << to_hex(upper_offset));
BEESTRACE("Checking haystack " << haystack << " offset " << to_hex(haystack_offset));
// Check all the blocks in the list
for (off_t haystack_offset = lower_offset; haystack_offset < upper_offset; haystack_offset += BLOCK_SIZE_CLONE) {
THROW_CHECK1(out_of_range, haystack_offset, (haystack_offset & BLOCK_MASK_CLONE) == 0);
THROW_CHECK1(out_of_range, haystack_offset, (haystack_offset & BLOCK_MASK_CLONE) == 0);
// Straw cannot extend beyond end of haystack
if (haystack_offset + needle.size() > haystack_size) {
BEESCOUNT(adjust_needle_too_long);
break;
}
// Read the haystack
BEESTRACE("straw " << name_fd(haystack.fd()) << ", offset " << to_hex(haystack_offset) << ", length " << needle.size());
BeesBlockData straw(haystack.fd(), haystack_offset, needle.size());
BEESTRACE("straw = " << straw);
// Stop if we find a match
if (straw.is_data_equal(needle)) {
BEESCOUNT(adjust_hit);
m_found_data = true;
m_found_hash = true;
if (is_compressed_offset) BEESCOUNT(adjust_compressed_offset_correct);
if (is_legacy) BEESCOUNT(adjust_legacy_correct);
if (is_exact) BEESCOUNT(adjust_exact_correct);
return straw;
}
if (straw.hash() != needle.hash()) {
// Not the same hash or data, try next block
BEESCOUNT(adjust_miss);
continue;
}
// Found the hash but not the data. Yay!
m_found_hash = true;
BEESLOGINFO("HASH COLLISION\n"
<< "\tneedle " << needle << "\n"
<< "\tstraw " << straw);
BEESCOUNT(hash_collision);
// Straw cannot extend beyond end of haystack
if (haystack_offset + needle.size() > haystack_size) {
BEESCOUNT(adjust_needle_too_long);
return BeesBlockData();
}
// Read the haystack
BEESTRACE("straw " << name_fd(haystack.fd()) << ", offset " << to_hex(haystack_offset) << ", length " << needle.size());
BeesBlockData straw(haystack.fd(), haystack_offset, needle.size());
BEESTRACE("straw = " << straw);
// Stop if we find a match
if (straw.is_data_equal(needle)) {
BEESCOUNT(adjust_hit);
m_found_data = true;
m_found_hash = true;
if (is_compressed_offset) BEESCOUNT(adjust_compressed_offset_correct);
if (is_exact) BEESCOUNT(adjust_exact_correct);
return straw;
}
if (straw.hash() != needle.hash()) {
// Not the same hash or data, try next block
BEESCOUNT(adjust_miss);
return BeesBlockData();
}
// Found the hash but not the data. Yay!
m_found_hash = true;
BEESLOGINFO("HASH COLLISION\n"
<< "\tneedle " << needle << "\n"
<< "\tstraw " << straw);
BEESCOUNT(hash_collision);
// Ran out of offsets to try
BEESCOUNT(adjust_no_match);
if (is_compressed_offset) BEESCOUNT(adjust_compressed_offset_wrong);
if (is_legacy) BEESCOUNT(adjust_legacy_wrong);
if (is_exact) BEESCOUNT(adjust_exact_wrong);
m_wrong_data = true;
return BeesBlockData();