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add exhaustive mode (-e) and cumulative results
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@dbry
dbry committed Jul 17, 2020
1 parent 6d18418 commit f8c1722
Showing 1 changed file with 86 additions and 57 deletions.
143 changes: 86 additions & 57 deletions lzwtester.c
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Original file line number Diff line number Diff line change
Expand Up @@ -25,19 +25,22 @@
*
* It can also optionally perform fuzz testing by randomly corrupting the
* compressed bitstream. Obviously this will introduce integrity failures,
* but it should not cause a crash.
* but it should not cause a crash. It also has an "exhaustive" mode that
* creates hundreds of simulated images from each input file by successive
* truncation from both ends.
*/

static const char *usage =
" Usage: lzwtester [options] file [...]\n\n"
" Options: -1 ... -8 = test using only specified max symbol size (9 - 16)\n"
" -0 = cycle through all maximum symbol sizes (default)\n"
" -e = exhaustive test (by successive truncation)\n"
" -f = fuzz test (randomly corrupt compressed data)\n"
" -q = quiet mode (only reports errors and summary)\n\n"
" Web: Visit www.github.com/dbry/lzw-ab for latest version and info\n\n";

typedef struct {
int size, index, wrapped, byte_errors, first_error, fuzz_testing;
unsigned int size, index, wrapped, byte_errors, first_error, fuzz_testing;
unsigned char *buffer;
} streamer;

Expand Down Expand Up @@ -129,7 +132,9 @@ long long DoGetFileSize (FILE *hFile)

int main (int argc, char **argv)
{
int index, checked = 0, tests = 0, skipped = 0, errors = 0, set_maxbits = 0, quiet_mode = 0;
int index, checked = 0, tests = 0, skipped = 0, errors = 0;
int set_maxbits = 0, quiet_mode = 0, exhaustive_mode = 0;
long long total_input_bytes = 0, total_output_bytes = 0;
streamer reader, writer, checker;

memset (&reader, 0, sizeof (reader));
Expand All @@ -143,7 +148,8 @@ int main (int argc, char **argv)

for (index = 1; index < argc; ++index) {
const char *filename = argv [index];
int bytes_read, maxbits;
int test_size, bytes_read, maxbits;
unsigned char *file_buffer;
long long file_size;
FILE *infile;

Expand All @@ -152,6 +158,11 @@ int main (int argc, char **argv)
continue;
}

if (!strcmp (filename, "-e")) {
exhaustive_mode = 1;
continue;
}

if (!strcmp (filename, "-f")) {
writer.fuzz_testing = 1;
continue;
Expand Down Expand Up @@ -188,101 +199,119 @@ int main (int argc, char **argv)
continue;
}

reader.buffer = malloc (reader.size = (int) file_size);
writer.buffer = malloc (writer.size = (int) (file_size + file_size + 10));
file_buffer = malloc (file_size);
writer.size = (unsigned int)(file_size * 2 + 10);
writer.buffer = malloc (writer.size);

if (!reader.buffer || !writer.buffer) {
if (!file_buffer || !writer.buffer) {
printf ("\nfile %s is too big!\n", filename);
if (writer.buffer) free (writer.buffer);
if (reader.buffer) free (reader.buffer);
if (file_buffer) free (file_buffer);
skipped++;
continue;
}

bytes_read = fread (reader.buffer, 1, (int) file_size, infile);
bytes_read = fread (file_buffer, 1, (int) file_size, infile);
fclose (infile);

if (bytes_read != (int) file_size) {
printf ("\nfile %s could not be read!\n", filename);
free (writer.buffer);
free (reader.buffer);
free (file_buffer);
skipped++;
continue;
}

if (!quiet_mode)
printf ("\n");

test_size = file_size;
checked++;

for (maxbits = set_maxbits ? set_maxbits : 9; maxbits <= (set_maxbits ? set_maxbits : 16); ++maxbits) {
int res, got_error = 0;
do {
for (maxbits = set_maxbits ? set_maxbits : 9; maxbits <= (set_maxbits ? set_maxbits : 16); ++maxbits) {
int res, got_error = 0;

reader.index = writer.index = writer.wrapped = 0;
reader.buffer = file_buffer + (file_size - test_size) / 2;
reader.size = test_size;

if (lzw_compress (write_buff, &writer, read_buff, &reader, maxbits)) {
printf ("\nlzw_compress() returned error on file %s, maxbits = %d\n", filename, maxbits);
errors++;
continue;
}
reader.index = writer.index = writer.wrapped = 0;

if (writer.wrapped) {
printf ("\nover 100%% inflation on file %s, maxbits = %d!\n", filename, maxbits);
errors++;
continue;
}
if (lzw_compress (write_buff, &writer, read_buff, &reader, maxbits)) {
printf ("\nlzw_compress() returned error on file %s, maxbits = %d\n", filename, maxbits);
errors++;
continue;
}

checker.buffer = reader.buffer;
checker.size = reader.size;
checker.wrapped = checker.byte_errors = checker.index = 0;
if (writer.wrapped) {
printf ("\nover 100%% inflation on file %s, maxbits = %d!\n", filename, maxbits);
errors++;
continue;
}

reader.buffer = writer.buffer;
reader.size = writer.index;
reader.index = 0;
checker.buffer = reader.buffer;
checker.size = reader.size;
checker.wrapped = checker.byte_errors = checker.index = 0;

res = lzw_decompress (check_buff, &checker, read_buff, &reader);
reader.buffer = writer.buffer;
reader.size = writer.index;
reader.index = 0;

reader.buffer = checker.buffer;
reader.size = checker.size;
res = lzw_decompress (check_buff, &checker, read_buff, &reader);

got_error = res || checker.index != checker.size || checker.wrapped || checker.byte_errors;
reader.buffer = checker.buffer;
reader.size = checker.size;

if (!quiet_mode || got_error)
printf ("file %s, maxbits = %2d: %d bytes --> %d bytes, %.2f%%\n", filename, maxbits,
reader.size, writer.index, writer.index * 100.0 / reader.size);
got_error = res || checker.index != checker.size || checker.wrapped || checker.byte_errors;

if (got_error) {
if (res)
printf ("decompressor returned an error\n");
if (!quiet_mode || got_error)
printf ("file %s, maxbits = %2d: %u bytes --> %u bytes, %.2f%%\n", filename, maxbits,
reader.size, writer.index, writer.index * 100.0 / reader.size);

if (!checker.index)
printf ("decompression didn't generate any data\n");
else if (checker.index != checker.size)
printf ("decompression terminated %d bytes early\n", checker.size - checker.index);
else if (checker.wrapped)
printf ("decompression generated %d extra bytes\n", checker.wrapped);
if (got_error) {
if (res)
printf ("decompressor returned an error\n");

if (checker.byte_errors)
printf ("there were %d byte data errors starting at index %d\n",
checker.byte_errors, checker.first_error);
else if (checker.index != checker.size || checker.wrapped)
printf ("(but the data generated was all correct)\n");
if (!checker.index)
printf ("decompression didn't generate any data\n");
else if (checker.index != checker.size)
printf ("decompression terminated %u bytes early\n", checker.size - checker.index);
else if (checker.wrapped)
printf ("decompression generated %u extra bytes\n", checker.wrapped);

printf ("\n");
errors++;
if (checker.byte_errors)
printf ("there were %u byte data errors starting at index %u\n",
checker.byte_errors, checker.first_error);
else if (checker.index != checker.size || checker.wrapped)
printf ("(but the data generated was all correct)\n");

printf ("\n");
errors++;
}
else {
total_input_bytes += reader.size;
total_output_bytes += writer.index;
}

tests++;

if (exhaustive_mode)
test_size -= (test_size + 98) / 100;
}

tests++;
}
} while (exhaustive_mode && test_size > 1 && test_size > file_size / 100);

free (writer.buffer);
free (reader.buffer);
free (file_buffer);
}

if (errors)
printf ("\n***** %d errors detected in %d tests using %d files (%d skipped) *****\n\n", errors, tests, checked, skipped);
else
printf ("\nsuccessfully ran %d tests using %d files (%d skipped) with no errors detected\n\n", tests, checked, skipped);
else {
printf ("\nsuccessfully ran %d tests using %d files (%d skipped) with no errors detected\n", tests, checked, skipped);
printf ("cumulative results: %llu bytes --> %llu bytes, %.2f%%\n\n", total_input_bytes, total_output_bytes,
total_output_bytes * 100.0 / total_input_bytes);
}

return errors;
}

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