commit 1e1581a24ea11b93b1fdf33a11ce07b8d2772c75
Author: Nick Mathewson <nickm(a)torproject.org>
Date: Tue Apr 25 15:36:13 2017 -0400
Pre-compress consensus diffs with supported consensus methods.
---
src/or/consdiffmgr.c | 229 ++++++++++++++++++++++++++++++++------------
src/or/consdiffmgr.h | 4 +-
src/test/test_consdiffmgr.c | 11 ++-
3 files changed, 177 insertions(+), 67 deletions(-)
diff --git a/src/or/consdiffmgr.c b/src/or/consdiffmgr.c
index 2deeab5..9a3c56d 100644
--- a/src/or/consdiffmgr.c
+++ b/src/or/consdiffmgr.c
@@ -74,6 +74,25 @@ typedef enum cdm_diff_status_t {
CDM_DIFF_ERROR=3,
} cdm_diff_status_t;
+/** Which methods do we use for precompressing diffs? */
+static const compress_method_t compress_diffs_with[] = {
+ NO_METHOD,
+ GZIP_METHOD,
+#ifdef HAVE_LZMA
+ LZMA_METHOD,
+#endif
+#ifdef HAVE_ZSTD
+ ZSTD_METHOD,
+#endif
+};
+
+/** How many different methods will we try to use for diff compression? */
+STATIC unsigned
+n_diff_compression_methods(void)
+{
+ return ARRAY_LENGTH(compress_diffs_with);
+}
+
/** Hashtable node used to remember the current status of the diff
* from a given sha3 digest to the current consensus. */
typedef struct cdm_diff_t {
@@ -84,12 +103,15 @@ typedef struct cdm_diff_t {
/** SHA3-256 digest of the consensus that this diff is _from_. (part of the
* ht key) */
uint8_t from_sha3[DIGEST256_LEN];
+ /** Method by which the diff is compressed. (part of the ht key */
+ compress_method_t compress_method;
/** One of the CDM_DIFF_* values, depending on whether this diff
* is available, in progress, or impossible to compute. */
cdm_diff_status_t cdm_diff_status;
/** SHA3-256 digest of the consensus that this diff is _to. */
uint8_t target_sha3[DIGEST256_LEN];
+
/** Handle to the cache entry for this diff, if any. We use a handle here
* to avoid thinking too hard about cache entry lifetime issues. */
consensus_cache_entry_handle_t *entry;
@@ -121,9 +143,10 @@ static void consdiffmgr_set_cache_flags(void);
static unsigned
cdm_diff_hash(const cdm_diff_t *diff)
{
- uint8_t tmp[DIGEST256_LEN + 1];
+ uint8_t tmp[DIGEST256_LEN + 2];
memcpy(tmp, diff->from_sha3, DIGEST256_LEN);
tmp[DIGEST256_LEN] = (uint8_t) diff->flavor;
+ tmp[DIGEST256_LEN+1] = (uint8_t) diff->compress_method;
return (unsigned) siphash24g(tmp, sizeof(tmp));
}
/** Helper: compare two cdm_diff_t objects for key equality */
@@ -131,7 +154,8 @@ static int
cdm_diff_eq(const cdm_diff_t *diff1, const cdm_diff_t *diff2)
{
return fast_memeq(diff1->from_sha3, diff2->from_sha3, DIGEST256_LEN) &&
- diff1->flavor == diff2->flavor;
+ diff1->flavor == diff2->flavor &&
+ diff1->compress_method == diff2->compress_method;
}
HT_PROTOTYPE(cdm_diff_ht, cdm_diff_t, node, cdm_diff_hash, cdm_diff_eq)
@@ -153,13 +177,15 @@ cdm_diff_free(cdm_diff_t *diff)
static cdm_diff_t *
cdm_diff_new(consensus_flavor_t flav,
const uint8_t *from_sha3,
- const uint8_t *target_sha3)
+ const uint8_t *target_sha3,
+ compress_method_t method)
{
cdm_diff_t *ent;
ent = tor_malloc_zero(sizeof(cdm_diff_t));
ent->flavor = flav;
memcpy(ent->from_sha3, from_sha3, DIGEST256_LEN);
memcpy(ent->target_sha3, target_sha3, DIGEST256_LEN);
+ ent->compress_method = method;
return ent;
}
@@ -177,18 +203,25 @@ cdm_diff_ht_check_and_note_pending(consensus_flavor_t flav,
const uint8_t *target_sha3)
{
struct cdm_diff_t search, *ent;
- memset(&search, 0, sizeof(cdm_diff_t));
- search.flavor = flav;
- memcpy(search.from_sha3, from_sha3, DIGEST256_LEN);
- ent = HT_FIND(cdm_diff_ht, &cdm_diff_ht, &search);
- if (ent) {
- tor_assert_nonfatal(ent->cdm_diff_status != CDM_DIFF_PRESENT);
- return 1;
+ unsigned u;
+ int result = 0;
+ for (u = 0; u < n_diff_compression_methods(); ++u) {
+ compress_method_t method = compress_diffs_with[u];
+ memset(&search, 0, sizeof(cdm_diff_t));
+ search.flavor = flav;
+ search.compress_method = method;
+ memcpy(search.from_sha3, from_sha3, DIGEST256_LEN);
+ ent = HT_FIND(cdm_diff_ht, &cdm_diff_ht, &search);
+ if (ent) {
+ tor_assert_nonfatal(ent->cdm_diff_status != CDM_DIFF_PRESENT);
+ result = 1;
+ continue;
+ }
+ ent = cdm_diff_new(flav, from_sha3, target_sha3, method);
+ ent->cdm_diff_status = CDM_DIFF_IN_PROGRESS;
+ HT_INSERT(cdm_diff_ht, &cdm_diff_ht, ent);
}
- ent = cdm_diff_new(flav, from_sha3, target_sha3);
- ent->cdm_diff_status = CDM_DIFF_IN_PROGRESS;
- HT_INSERT(cdm_diff_ht, &cdm_diff_ht, ent);
- return 0;
+ return result;
}
/**
@@ -201,16 +234,18 @@ static void
cdm_diff_ht_set_status(consensus_flavor_t flav,
const uint8_t *from_sha3,
const uint8_t *to_sha3,
+ compress_method_t method,
int status,
consensus_cache_entry_handle_t *handle)
{
struct cdm_diff_t search, *ent;
memset(&search, 0, sizeof(cdm_diff_t));
search.flavor = flav;
+ search.compress_method = method,
memcpy(search.from_sha3, from_sha3, DIGEST256_LEN);
ent = HT_FIND(cdm_diff_ht, &cdm_diff_ht, &search);
if (!ent) {
- ent = cdm_diff_new(flav, from_sha3, to_sha3);
+ ent = cdm_diff_new(flav, from_sha3, to_sha3, method);
ent->cdm_diff_status = CDM_DIFF_IN_PROGRESS;
HT_INSERT(cdm_diff_ht, &cdm_diff_ht, ent);
} else if (fast_memneq(ent->target_sha3, to_sha3, DIGEST256_LEN)) {
@@ -500,7 +535,8 @@ consdiffmgr_find_diff_from(consensus_cache_entry_t **entry_out,
consensus_flavor_t flavor,
int digest_type,
const uint8_t *digest,
- size_t digestlen)
+ size_t digestlen,
+ compress_method_t method)
{
if (BUG(digest_type != DIGEST_SHA3_256) ||
BUG(digestlen != DIGEST256_LEN)) {
@@ -511,6 +547,7 @@ consdiffmgr_find_diff_from(consensus_cache_entry_t **entry_out,
cdm_diff_t search, *ent;
memset(&search, 0, sizeof(search));
search.flavor = flavor;
+ search.compress_method = method;
memcpy(search.from_sha3, digest, DIGEST256_LEN);
ent = HT_FIND(cdm_diff_ht, &cdm_diff_ht, &search);
@@ -820,6 +857,16 @@ consdiffmgr_diffs_load(void)
int flavor = networkstatus_parse_flavor_name(lv_flavor);
if (flavor < 0)
continue;
+ const char *lv_compression =
+ consensus_cache_entry_get_value(diff, LABEL_COMPRESSION_TYPE);
+ compress_method_t method = NO_METHOD;
+ if (lv_compression) {
+ method = compression_method_get_by_name(lv_compression);
+ if (method == UNKNOWN_METHOD) {
+ continue;
+ }
+ }
+
uint8_t from_sha3[DIGEST256_LEN];
uint8_t to_sha3[DIGEST256_LEN];
if (cdm_entry_get_sha3_value(from_sha3, diff, LABEL_FROM_SHA3_DIGEST)<0)
@@ -828,6 +875,7 @@ consdiffmgr_diffs_load(void)
continue;
cdm_diff_ht_set_status(flavor, from_sha3, to_sha3,
+ method,
CDM_DIFF_PRESENT,
consensus_cache_entry_handle_new(diff));
} SMARTLIST_FOREACH_END(diff);
@@ -896,6 +944,18 @@ consdiffmgr_free_all(void)
Thread workers
=====*/
+typedef struct compressed_result_t {
+ config_line_t *labels;
+ /**
+ * Output: Body of the diff, as compressed.
+ */
+ uint8_t *body;
+ /**
+ * Output: length of body_out
+ */
+ size_t bodylen;
+} compressed_result_t;
+
/**
* An object passed to a worker thread that will try to produce a consensus
* diff.
@@ -914,18 +974,8 @@ typedef struct consensus_diff_worker_job_t {
*/
consensus_cache_entry_t *diff_to;
- /**
- * Output: Labels to store in the cache associated with this diff.
- */
- config_line_t *labels_out;
- /**
- * Output: Body of the diff
- */
- uint8_t *body_out;
- /**
- * Output: length of body_out
- */
- size_t bodylen_out;
+ /** Output: labels and bodies */
+ compressed_result_t out[ARRAY_LENGTH(compress_diffs_with)];
} consensus_diff_worker_job_t;
/** Given a consensus_cache_entry_t, check whether it has a label claiming
@@ -1040,23 +1090,55 @@ consensus_diff_worker_threadfn(void *state_, void *work_)
return WQ_RPL_REPLY;
}
- /* Send the reply */
- job->body_out = (uint8_t *) consensus_diff;
- job->bodylen_out = strlen(consensus_diff);
-
- cdm_labels_prepend_sha3(&job->labels_out, LABEL_SHA3_DIGEST,
- job->body_out, job->bodylen_out);
- cdm_labels_prepend_sha3(&job->labels_out, LABEL_SHA3_DIGEST_UNCOMPRESSED,
- job->body_out, job->bodylen_out);
- config_line_prepend(&job->labels_out, LABEL_FROM_VALID_AFTER,
+ /* Compress the results and send the reply */
+ tor_assert(compress_diffs_with[0] == NO_METHOD);
+ size_t difflen = strlen(consensus_diff);
+ job->out[0].body = (uint8_t *) consensus_diff;
+ job->out[0].bodylen = difflen;
+
+ config_line_t *common_labels = NULL;
+ cdm_labels_prepend_sha3(&common_labels,
+ LABEL_SHA3_DIGEST_UNCOMPRESSED,
+ job->out[0].body,
+ job->out[0].bodylen);
+ config_line_prepend(&common_labels, LABEL_FROM_VALID_AFTER,
lv_from_valid_after);
- config_line_prepend(&job->labels_out, LABEL_VALID_AFTER, lv_to_valid_after);
- config_line_prepend(&job->labels_out, LABEL_FLAVOR, lv_from_flavor);
- config_line_prepend(&job->labels_out, LABEL_FROM_SHA3_DIGEST,
+ config_line_prepend(&common_labels, LABEL_VALID_AFTER,
+ lv_to_valid_after);
+ config_line_prepend(&common_labels, LABEL_FLAVOR, lv_from_flavor);
+ config_line_prepend(&common_labels, LABEL_FROM_SHA3_DIGEST,
lv_from_digest);
- config_line_prepend(&job->labels_out, LABEL_TARGET_SHA3_DIGEST,
+ config_line_prepend(&common_labels, LABEL_TARGET_SHA3_DIGEST,
lv_to_digest);
- config_line_prepend(&job->labels_out, LABEL_DOCTYPE, DOCTYPE_CONSENSUS_DIFF);
+ config_line_prepend(&common_labels, LABEL_DOCTYPE,
+ DOCTYPE_CONSENSUS_DIFF);
+
+ job->out[0].labels = config_lines_dup(common_labels);
+ cdm_labels_prepend_sha3(&job->out[0].labels,
+ LABEL_SHA3_DIGEST,
+ job->out[0].body,
+ job->out[0].bodylen);
+
+ unsigned u;
+ for (u = 1; u < n_diff_compression_methods(); ++u) {
+ compress_method_t method = compress_diffs_with[u];
+ const char *methodname = compression_method_get_name(method);
+ char *result;
+ size_t sz;
+ if (0 == tor_compress(&result, &sz, consensus_diff, difflen, method)) {
+ job->out[u].body = (uint8_t*)result;
+ job->out[u].bodylen = sz;
+ job->out[u].labels = config_lines_dup(common_labels);
+ cdm_labels_prepend_sha3(&job->out[u].labels, LABEL_SHA3_DIGEST,
+ job->out[u].body,
+ job->out[u].bodylen);
+ config_line_prepend(&job->out[u].labels,
+ LABEL_COMPRESSION_TYPE,
+ methodname);
+ }
+ }
+
+ config_free_lines(common_labels);
return WQ_RPL_REPLY;
}
@@ -1068,8 +1150,11 @@ consensus_diff_worker_job_free(consensus_diff_worker_job_t *job)
{
if (!job)
return;
- tor_free(job->body_out);
- config_free_lines(job->labels_out);
+ unsigned u;
+ for (u = 0; u < n_diff_compression_methods(); ++u) {
+ config_free_lines(job->out[u].labels);
+ tor_free(job->out[u].body);
+ }
consensus_cache_entry_decref(job->diff_from);
consensus_cache_entry_decref(job->diff_to);
tor_free(job);
@@ -1117,20 +1202,35 @@ consensus_diff_worker_replyfn(void *work_)
cache = 0;
}
- int status;
- consensus_cache_entry_handle_t *handle = NULL;
- if (job->body_out && job->bodylen_out && job->labels_out) {
- /* Success! Store the results */
- log_info(LD_DIRSERV, "Adding consensus diff from %s to %s",
- lv_from_digest, lv_to_digest);
- consensus_cache_entry_t *ent =
- consensus_cache_add(cdm_cache_get(), job->labels_out,
- job->body_out,
- job->bodylen_out);
- status = CDM_DIFF_PRESENT;
- handle = consensus_cache_entry_handle_new(ent);
- consensus_cache_entry_decref(ent);
- } else {
+ int status = CDM_DIFF_ERROR;
+ consensus_cache_entry_handle_t *handles[ARRAY_LENGTH(compress_diffs_with)];
+ memset(handles, 0, sizeof(handles));
+
+ unsigned u;
+ for (u = 0; u < n_diff_compression_methods(); ++u) {
+ compress_method_t method = compress_diffs_with[u];
+ uint8_t *body_out = job->out[u].body;
+ size_t bodylen_out = job->out[u].bodylen;
+ config_line_t *labels = job->out[u].labels;
+ const char *methodname = compression_method_get_name(method);
+ if (body_out && bodylen_out && labels) {
+ /* Success! Store the results */
+ log_info(LD_DIRSERV, "Adding consensus diff from %s to %s, "
+ "compressed with %s",
+ lv_from_digest, lv_to_digest, methodname);
+
+ consensus_cache_entry_t *ent =
+ consensus_cache_add(cdm_cache_get(),
+ labels,
+ body_out,
+ bodylen_out);
+
+ status = CDM_DIFF_PRESENT;
+ handles[u] = consensus_cache_entry_handle_new(ent);
+ consensus_cache_entry_decref(ent);
+ }
+ }
+ if (status != CDM_DIFF_PRESENT) {
/* Failure! Nothing to do but complain */
log_warn(LD_DIRSERV,
"Worker was unable to compute consensus diff "
@@ -1139,10 +1239,15 @@ consensus_diff_worker_replyfn(void *work_)
status = CDM_DIFF_ERROR;
}
- if (cache)
- cdm_diff_ht_set_status(flav, from_sha3, to_sha3, status, handle);
- else
- consensus_cache_entry_handle_free(handle);
+ for (u = 0; u < ARRAY_LENGTH(handles); ++u) {
+ compress_method_t method = compress_diffs_with[u];
+ if (cache) {
+ cdm_diff_ht_set_status(flav, from_sha3, to_sha3, method, status,
+ handles[u]);
+ } else {
+ consensus_cache_entry_handle_free(handles[u]);
+ }
+ }
consensus_diff_worker_job_free(job);
}
diff --git a/src/or/consdiffmgr.h b/src/or/consdiffmgr.h
index 982e0df..1279673 100644
--- a/src/or/consdiffmgr.h
+++ b/src/or/consdiffmgr.h
@@ -28,7 +28,8 @@ consdiff_status_t consdiffmgr_find_diff_from(
consensus_flavor_t flavor,
int digest_type,
const uint8_t *digest,
- size_t digestlen);
+ size_t digestlen,
+ compress_method_t method);
void consdiffmgr_rescan(void);
int consdiffmgr_cleanup(void);
void consdiffmgr_configure(const consdiff_cfg_t *cfg);
@@ -36,6 +37,7 @@ void consdiffmgr_free_all(void);
int consdiffmgr_validate(void);
#ifdef CONSDIFFMGR_PRIVATE
+STATIC unsigned n_diff_compression_methods(void);
STATIC consensus_cache_t *cdm_cache_get(void);
STATIC consensus_cache_entry_t *cdm_cache_lookup_consensus(
consensus_flavor_t flavor, time_t valid_after);
diff --git a/src/test/test_consdiffmgr.c b/src/test/test_consdiffmgr.c
index b3fa388..31ce6ce 100644
--- a/src/test/test_consdiffmgr.c
+++ b/src/test/test_consdiffmgr.c
@@ -141,7 +141,8 @@ lookup_diff_from(consensus_cache_entry_t **out,
uint8_t digest[DIGEST256_LEN];
crypto_digest256((char*)digest, str1, strlen(str1), DIGEST_SHA3_256);
return consdiffmgr_find_diff_from(out, flav,
- DIGEST_SHA3_256, digest, sizeof(digest));
+ DIGEST_SHA3_256, digest, sizeof(digest),
+ NO_METHOD);
}
static int
@@ -373,7 +374,8 @@ test_consdiffmgr_make_diffs(void *arg)
tt_int_op(1, OP_EQ, smartlist_len(fake_cpuworker_queue));
diff_status = consdiffmgr_find_diff_from(&diff, FLAV_MICRODESC,
DIGEST_SHA3_256,
- md_ns_sha3, DIGEST256_LEN);
+ md_ns_sha3, DIGEST256_LEN,
+ NO_METHOD);
tt_int_op(CONSDIFF_IN_PROGRESS, OP_EQ, diff_status);
// Now run that process and get the diff.
@@ -384,7 +386,8 @@ test_consdiffmgr_make_diffs(void *arg)
// At this point we should be able to get that diff.
diff_status = consdiffmgr_find_diff_from(&diff, FLAV_MICRODESC,
DIGEST_SHA3_256,
- md_ns_sha3, DIGEST256_LEN);
+ md_ns_sha3, DIGEST256_LEN,
+ NO_METHOD);
tt_int_op(CONSDIFF_AVAILABLE, OP_EQ, diff_status);
tt_assert(diff);
@@ -757,7 +760,7 @@ test_consdiffmgr_cleanup_old_diffs(void *arg)
/* Now add an even-more-recent consensus; this should make all previous
* diffs deletable */
tt_int_op(0, OP_EQ, consdiffmgr_add_consensus(md_body[3], md_ns[3]));
- tt_int_op(2, OP_EQ, consdiffmgr_cleanup());
+ tt_int_op(2 * n_diff_compression_methods(), OP_EQ, consdiffmgr_cleanup());
tt_int_op(CONSDIFF_NOT_FOUND, OP_EQ,
lookup_diff_from(&ent, FLAV_MICRODESC, md_body[0]));