commit 6da31ec4848b23db4b923ff5141c24b82f466c8d Author: Nick Mathewson nickm@torproject.org Date: Fri May 5 10:48:02 2017 -0400

consdiffmgr: Extract the code for compressing and storing

We're going to use this for consensuses too. --- src/or/consdiffmgr.c | 142 +++++++++++++++++++++++++++++++++++---------------- 1 file changed, 99 insertions(+), 43 deletions(-)

diff --git a/src/or/consdiffmgr.c b/src/or/consdiffmgr.c index d478101..b108c80 100644 --- a/src/or/consdiffmgr.c +++ b/src/or/consdiffmgr.c @@ -1072,6 +1072,91 @@ typedef struct compressed_result_t { } compressed_result_t;

/** + * Compress the bytestring <b>input</b> of length <b>len</b> using the + * <n>n_methods</b> compression methods listed in the array <b>methods</b>. + * + * For each successful compression, set the fields in the <b>results_out</b> + * array in the position corresponding to the compression method. Use + * <b>labels_in</b> as a basis for the labels of the result. + * + * Return 0 if all compression succeeded; -1 if any failed. + */ +static int +compress_multiple(compressed_result_t *results_out, int n_methods, + const compress_method_t *methods, + const uint8_t *input, size_t len, + const config_line_t *labels_in) +{ + int rv = 0; + int i; + for (i = 0; i < n_methods; ++i) { + compress_method_t method = methods[i]; + const char *methodname = compression_method_get_name(method); + char *result; + size_t sz; + if (0 == tor_compress(&result, &sz, (const char*)input, len, method)) { + results_out[i].body = (uint8_t*)result; + results_out[i].bodylen = sz; + results_out[i].labels = config_lines_dup(labels_in); + cdm_labels_prepend_sha3(&results_out[i].labels, LABEL_SHA3_DIGEST, + results_out[i].body, + results_out[i].bodylen); + config_line_prepend(&results_out[i].labels, + LABEL_COMPRESSION_TYPE, + methodname); + } else { + rv = -1; + } + } + return rv; +} + +/** + * Given an array of <b>n</b> compressed_result_t in <b>results</b>, + * as produced by compress_multiple, store them all into the + * consdiffmgr, and store handles to them in the <b>handles_out</b> + * array. + * + * Return CDM_DIFF_PRESENT if any was stored, and CDM_DIFF_ERROR if none + * was stored. + */ +static cdm_diff_status_t +store_multiple(consensus_cache_entry_handle_t **handles_out, + int n, + const compress_method_t *methods, + const compressed_result_t *results, + const char *description) +{ + cdm_diff_status_t status = CDM_DIFF_ERROR; + consdiffmgr_ensure_space_for_files(n); + + int i; + for (i = 0; i < n; ++i) { + compress_method_t method = methods[i]; + uint8_t *body_out = results[i].body; + size_t bodylen_out = results[i].bodylen; + config_line_t *labels = results[i].labels; + const char *methodname = compression_method_get_name(method); + if (body_out && bodylen_out && labels) { + /* Success! Store the results */ + log_info(LD_DIRSERV, "Adding %s, compressed with %s", + description, methodname); + + consensus_cache_entry_t *ent = + consensus_cache_add(cdm_cache_get(), + labels, + body_out, + bodylen_out); + + status = CDM_DIFF_PRESENT; + handles_out[i] = consensus_cache_entry_handle_new(ent); + consensus_cache_entry_decref(ent); + } + } + return status; +} + +/** * An object passed to a worker thread that will try to produce a consensus * diff. */ @@ -1235,24 +1320,10 @@ consensus_diff_worker_threadfn(void *state_, void *work_) 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); - } - } + compress_multiple(job->out+1, + n_diff_compression_methods()-1, + compress_diffs_with+1, + (const uint8_t*)consensus_diff, difflen, common_labels);

config_free_lines(common_labels); return WQ_RPL_REPLY; @@ -1318,36 +1389,20 @@ consensus_diff_worker_replyfn(void *work_) cache = 0; }

- int status = CDM_DIFF_ERROR; consensus_cache_entry_handle_t *handles[ARRAY_LENGTH(compress_diffs_with)]; memset(handles, 0, sizeof(handles));

- consdiffmgr_ensure_space_for_files(n_diff_compression_methods()); + char description[128]; + tor_snprintf(description, sizeof(description), + "consensus diff from %s to %s", + lv_from_digest, lv_to_digest);

- 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); + int status = store_multiple(handles, + n_diff_compression_methods(), + compress_diffs_with, + job->out, + description);

- 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, @@ -1357,6 +1412,7 @@ consensus_diff_worker_replyfn(void *work_) status = CDM_DIFF_ERROR; }

+ unsigned u; for (u = 0; u < ARRAY_LENGTH(handles); ++u) { compress_method_t method = compress_diffs_with[u]; if (cache) {