Rename input.h to bitsource.h (and friends).

[fjl] / bitsource_test.c

diff --git a/bitsource_test.c b/bitsource_test.c
new file mode 100644 (file)
index 0000000..2b5217f
--- /dev/null
+++ b/bitsource_test.c
@@ -0,0 +1,130 @@
+#include <stdio.h>
+#include <string.h>
+#include <assert.h>
+#include <time.h>
+#include <sys/time.h>
+
+#include "bitsource.h"
+
+struct custom_read_userdata {
+       uint8_t* bytes;
+       unsigned bytes_left;
+};
+
+ssize_t custom_read(void* userdata, uint8_t* buf, size_t count)
+{
+       struct custom_read_userdata* ud = (struct custom_read_userdata*)userdata;
+       size_t num_to_read = (ud->bytes_left > count ? count : ud->bytes_left);
+       memcpy(buf, ud->bytes, num_to_read);
+       ud->bytes += num_to_read;
+       ud->bytes_left -= num_to_read;
+       return num_to_read;     
+}
+
+ssize_t custom_read_slow(void* userdata, uint8_t* buf, size_t count)
+{
+       struct custom_read_userdata* ud = (struct custom_read_userdata*)userdata;
+       size_t num_to_read = ((count > 0 && ud->bytes_left > 0) ? 1 : 0);
+       memcpy(buf, ud->bytes, num_to_read);
+       ud->bytes += num_to_read;
+       ud->bytes_left -= num_to_read;
+       return num_to_read;
+}
+
+// Read 6 bits at a time. We should get 0b101010 every time.
+void test_basic_reading()
+{
+       uint8_t bytes[] = { 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa };
+       struct custom_read_userdata ud;
+       ud.bytes = bytes;
+       ud.bytes_left = sizeof(bytes);
+
+       struct bit_source source;
+       init_bit_source(&source, custom_read, &ud);
+
+       for (unsigned i = 0; i < sizeof(bytes) * 8 / 6; ++i) {
+               possibly_refill(&source, 6);
+               unsigned ret = read_bits(&source, 6);
+               assert(ret == 0x2a);
+       }
+
+       assert(ud.bytes_left == 0);
+}
+
+// Same, but with an input source that gives back only one byte at a time.
+void test_slow_source()
+{
+       uint8_t bytes[] = { 0xaa, 0xaa, 0xaa, 0xaa, 0xaa, 0xaa };
+       struct custom_read_userdata ud;
+       ud.bytes = bytes;
+       ud.bytes_left = sizeof(bytes);
+
+       struct bit_source source;
+       init_bit_source(&source, custom_read_slow, &ud);
+
+       for (unsigned i = 0; i < sizeof(bytes) * 8 / 6; ++i) {
+               possibly_refill(&source, 6);
+               unsigned ret = read_bits(&source, 6);
+               assert(ret == 0x2a);
+       }
+
+       assert(ud.bytes_left == 0);
+}
+
+// Read a few different bit sizes.
+void test_variable_size()
+{
+       uint8_t bytes[] = { 0x12, 0x34, 0x56, 0x78, 0xff };
+       struct custom_read_userdata ud;
+       ud.bytes = bytes;
+       ud.bytes_left = sizeof(bytes);
+
+       struct bit_source source;
+       init_bit_source(&source, custom_read, &ud);
+
+       {
+               possibly_refill(&source, 4);
+               unsigned ret = read_bits(&source, 1);
+               assert(ret == 0x0);
+               ret = read_bits(&source, 1);
+               assert(ret == 0x0);
+               ret = read_bits(&source, 1);
+               assert(ret == 0x0);
+               ret = read_bits(&source, 1);
+               assert(ret == 0x1);
+       }
+       {
+               possibly_refill(&source, 4);
+               unsigned ret = read_bits(&source, 4);
+               assert(ret == 0x2);
+       }
+       {
+               possibly_refill(&source, 12);
+               unsigned ret = read_bits(&source, 12);
+               assert(ret == 0x345);
+       }
+       {
+               possibly_refill(&source, 20);
+               unsigned ret = read_bits(&source, 16);
+               assert(ret == 0x678f);
+               ret = read_bits(&source, 4);
+               assert(ret == 0xf);
+       }
+
+       assert(ud.bytes_left == 0);
+}
+
+int main(void)
+{
+       printf("test_basic_reading()\n");
+       test_basic_reading();
+       
+       printf("test_slow_source()\n");
+       test_slow_source();
+       
+       printf("test_variable_size()\n");
+       test_variable_size();
+       
+       printf("All tests pass.\n");
+       return 0;
+}