kv: Support garbage collection from userspace

Signed-off-by: Alistair Francis <[email protected]>

examples/tests/kv/kv_unit_tests/Makefile

@@ -6,7 +6,9 @@ TOCK_USERLAND_BASE_DIR = ../../../..
 # Which files to compile.
 C_SRCS := $(wildcard *.c)
 
-ELF2TAB_ARGS += --write_id 17767 --read_ids 17767 --access_ids 17767
+# Magic numbers that have to allign with what the kernel gives this
+# application as a short ID.
+ELF2TAB_ARGS += --write_id 1153320202 --read_ids 1153320202 --access_ids 1153320202
 
 # Include userland master makefile. Contains rules and flags for actually
 # building the application.

examples/tests/kv/kv_unit_tests/main.c

@@ -394,6 +394,50 @@ static bool test_set_get_32regions_8(void) {
   return subtest_set_get_region(28, 32);
 }
 
+static bool test_garbage_collect(void) {
+  int ret;
+  char key[] = "kvtestapp";
+  strcpy((char*) key_buf, key);
+  int num_of_keys    = 0;
+  uint32_t value_len = 500;
+
+  printf("Filling up storage with invalid (deleted) keys\r\n");
+
+  // Fill up the storage
+  do {
+    for (uint32_t i = 0; i < value_len; i++) {
+      value_buf[i] = num_of_keys;
+    }
+
+    printf("Setting key %d\r\n", num_of_keys);
+    ret = libtocksync_kv_set(key_buf, strlen(key), value_buf, value_len);
+
+    if (ret == RETURNCODE_SUCCESS) {
+      num_of_keys++;
+    }
+  } while (ret == RETURNCODE_SUCCESS);
+
+  printf("Wrote %d K/V entries to flash, running garbage collection\n", num_of_keys);
+
+  ret = libtocksync_kv_garbage_collect();
+  CHECK(ret == RETURNCODE_SUCCESS);
+
+  printf("Garbage collection finished, trying to re-set the keys\r\n");
+
+  for (int i = 0; i < num_of_keys; i++) {
+    printf("Setting key %d\r\n", i);
+    for (uint32_t j = 0; j < value_len; j++) {
+      value_buf[j] = i;
+    }
+
+    CHECK(libtocksync_kv_set(key_buf, strlen(key), value_buf, value_len) == RETURNCODE_SUCCESS);
+  }
+
+  printf("Set all keys\r\n");
+
+  return true;
+}
+
 int main(void) {
   unit_test_fun tests[] = {
     TEST(exists),
@@ -419,6 +463,7 @@ int main(void) {
     TEST(set_get_32regions_6),
     TEST(set_get_32regions_7),
     TEST(set_get_32regions_8),
+    TEST(garbage_collect),
   };
   unit_test_runner(tests, sizeof(tests) / sizeof(unit_test_fun), 2000, "org.tockos.unit_test");
   return 0;

libtock-sync/storage/kv.c

@@ -78,3 +78,15 @@ returncode_t libtocksync_kv_delete(const uint8_t* key_buffer, uint32_t key_len)
   yield_for(&result.fired);
   return result.ret;
 }
+
+returncode_t libtocksync_kv_garbage_collect(void) {
+  returncode_t err;
+  result.fired = false;
+
+  err = libtock_kv_garbage_collect(kv_cb_done);
+  if (err != RETURNCODE_SUCCESS) return err;
+
+  // Wait for the callback.
+  yield_for(&result.fired);
+  return result.ret;
+}

libtock-sync/storage/kv.h

@@ -21,6 +21,8 @@ returncode_t libtocksync_kv_update(const uint8_t* key_buffer, uint32_t key_len,
 
 returncode_t libtocksync_kv_delete(const uint8_t* key_buffer, uint32_t key_len);
 
+returncode_t libtocksync_kv_garbage_collect(void);
+
 #ifdef __cplusplus
 }
 #endif

libtock/storage/kv.c

@@ -81,3 +81,13 @@ returncode_t libtock_kv_delete(const uint8_t* key_buffer, uint32_t key_len, libt
   err = libtock_kv_command_delete();
   return err;
 }
+
+returncode_t libtock_kv_garbage_collect(libtock_kv_callback_done cb) {
+  returncode_t err;
+
+  err = libtock_kv_set_upcall(kv_upcall_done, cb);
+  if (err != RETURNCODE_SUCCESS) return err;
+
+  err = libtock_kv_command_garbage_collect();
+  return err;
+}

libtock/storage/kv.h

@@ -33,6 +33,7 @@ returncode_t libtock_kv_update(const uint8_t* key_buffer, uint32_t key_len, cons
 
 returncode_t libtock_kv_delete(const uint8_t* key_buffer, uint32_t key_len, libtock_kv_callback_done cb);
 
+returncode_t libtock_kv_garbage_collect(libtock_kv_callback_done cb);
 
 #ifdef __cplusplus
 }

libtock/storage/syscalls/kv_syscalls.c

@@ -11,6 +11,7 @@
 #define TOCK_KV_DELETE          3
 #define TOCK_KV_ADD             4
 #define TOCK_KV_UPDATE          5
+#define TOCK_KV_GARBAGE_COLLECT 6
 
 bool libtock_kv_exists(void) {
   return driver_exists(DRIVER_NUM_KV);
@@ -51,6 +52,11 @@ returncode_t libtock_kv_command_delete(void) {
   return tock_command_return_novalue_to_returncode(cval);
 }
 
+returncode_t libtock_kv_command_garbage_collect(void) {
+  syscall_return_t cval = command(DRIVER_NUM_KV, TOCK_KV_GARBAGE_COLLECT, 0, 0);
+  return tock_command_return_novalue_to_returncode(cval);
+}
+
 returncode_t libtock_kv_command_add(void) {
   syscall_return_t cval = command(DRIVER_NUM_KV, TOCK_KV_ADD, 0, 0);
   return tock_command_return_novalue_to_returncode(cval);

libtock/storage/syscalls/kv_syscalls.h

@@ -24,6 +24,8 @@ returncode_t libtock_kv_command_set(void);
 
 returncode_t libtock_kv_command_delete(void);
 
+returncode_t libtock_kv_command_garbage_collect(void);
+
 returncode_t libtock_kv_command_add(void);
 
 returncode_t libtock_kv_command_update(void);