feat(lander): support DELETE requests

include/lander.h

@@ -4,7 +4,7 @@
 #include "http_loop.h"
 #include "lsm/store.h"
 
-extern http_route lander_routes[4];
+extern http_route lander_routes[5];
 
 typedef struct lander_gctx {
   const char *data_dir;
@@ -57,4 +57,6 @@ bool lander_get_entry_lsm(event_loop_conn *conn);
 
 bool lander_post_redirect_body_to_attr(event_loop_conn *conn);
 
+bool lander_remove_entry(event_loop_conn *conn);
+
 #endif

lsm/example/test.c

@@ -20,18 +20,13 @@ int main() {
 
   lsm_str *attr;
   lsm_str_init_copy(&attr, "some attribute value");
-  lsm_entry_attr_insert(handle, lsm_attr_type_content_type, attr);
+  lsm_entry_attr_insert(handle, 1, attr);
 
   lsm_str *data;
   lsm_str_init_copy(&data, "hello");
 
   for (int i = 0; i < 50; i++) {
-    lsm_entry_data_append(store, handle, data);
-  }
-
-  if (lsm_entry_sync(store, handle) != lsm_error_ok) {
-    printf("godver");
-    return 1;
+    lsm_entry_data_append(handle, data);
   }
   lsm_entry_close(handle);
 
@@ -50,4 +45,12 @@ int main() {
     total += read;
   }
   printf("\n%lu", total);
+
+  lsm_entry_close(handle);
+
+  assert(lsm_store_open_write(&handle, store, key) == lsm_error_ok);
+  lsm_entry_remove(handle);
+  lsm_entry_close(handle);
+
+  assert(lsm_store_open_read(&handle, store, key) == lsm_error_not_found);
 }

lsm/include/lsm/store.h

@@ -176,6 +176,13 @@ void lsm_entry_close(lsm_entry_handle *handle);
 lsm_error lsm_store_insert(lsm_entry_handle **out, lsm_store *store,
                            lsm_str *key);
 
+/**
+ * Mark the entry as removed.
+ *
+ * @param handle handle to entry to remove
+ */
+void lsm_entry_remove(lsm_entry_handle *handle);
+
 /**
  * Append new data to the given entry, which is expected to be in the store.
  *

lsm/src/_include/lsm/store_internal.h

@@ -10,6 +10,7 @@
 
 #define LSM_DB_FILE_NAME "lsm.db"
 #define LSM_IDX_FILE_NAME "lsm.idx"
+#define LSM_DATA_FILE_SUFFIX ".data"
 
 typedef struct lsm_attr {
   uint8_t type;
@@ -40,6 +41,13 @@ typedef struct lsm_entry {
  */
 lsm_error lsm_entry_init(lsm_entry **ptr);
 
+/**
+ * Deallocate an existing entry
+ *
+ * @param entry pointer to entry
+ */
+void lsm_entry_free(lsm_entry *entry);
+
 /**
  * Deallocate an existing lsm_entry object.
  *
@@ -122,4 +130,15 @@ lsm_error lsm_entry_disk_remove(lsm_entry_handle *handle);
  */
 lsm_error lsm_entry_disk_update(lsm_entry_handle *handle);
 
+/**
+ * Return the length of the path to this entry's data file
+ */
+uint64_t lsm_entry_data_path_len(lsm_entry_handle *handle);
+
+/**
+ * Fill in the entry's data file path in the provided buffer. Use
+ * `lsm_entry_data_path_len` to allocate an appropriately-sized buffer
+ */
+void lsm_entry_data_path(char *buf, lsm_entry_handle *handle);
+
 #endif

lsm/src/store/lsm_store.c

@@ -158,6 +158,10 @@ lsm_error lsm_store_insert(lsm_entry_handle **out, lsm_store *store,
   return lsm_error_ok;
 }
 
+void lsm_entry_remove(lsm_entry_handle *handle) {
+  handle->states |= lsm_entry_handle_state_removed;
+}
+
 lsm_error lsm_entry_data_append(lsm_entry_handle *handle, lsm_str *data) {
   if (lsm_str_len(data) == 0) {
     return lsm_error_ok;
@@ -170,11 +174,10 @@ lsm_error lsm_entry_data_append(lsm_entry_handle *handle, lsm_str *data) {
 
   // Entries don't open their file unless needed
   if (handle->f == NULL) {
-    char path[handle->store->data_path->len + entry->key->len + 2];
-    sprintf(path, "%s/%s", lsm_str_ptr(handle->store->data_path),
-            lsm_str_ptr(entry->key));
+    char data_path[lsm_entry_data_path_len(handle) + 1];
+    lsm_entry_data_path(data_path, handle);
 
-    FILE *f = fopen(path, "ab");
+    FILE *f = fopen(data_path, "ab");
 
     if (f == NULL) {
       return lsm_error_failed_io;
@@ -209,11 +212,10 @@ lsm_error lsm_entry_data_read(uint64_t *out, char *buf,
 
   // Entries don't open their file unless needed
   if (handle->f == NULL) {
-    char path[handle->store->data_path->len + entry->key->len + 2];
-    sprintf(path, "%s/%s", lsm_str_ptr(handle->store->data_path),
-            lsm_str_ptr(entry->key));
+    char data_path[lsm_entry_data_path_len(handle) + 1];
+    lsm_entry_data_path(data_path, handle);
 
-    FILE *f = fopen(path, "rb");
+    FILE *f = fopen(data_path, "rb");
 
     if (f == NULL) {
       return lsm_error_failed_io;

lsm/src/store/lsm_store_disk_write.c

@@ -124,3 +124,49 @@ lsm_error lsm_entry_disk_insert(lsm_entry_handle *handle) {
 
   return res;
 }
+
+// Marking an entry as removed in the idx file is simply setting the length of
+// its entry to zero
+lsm_error lsm_entry_disk_remove(lsm_entry_handle *handle) {
+  lsm_store *store = handle->store;
+  lsm_entry *entry = handle->wrapper->entry;
+
+  pthread_mutex_lock(&store->idx.lock);
+
+  lsm_error res =
+      lsm_fseek(store->idx.f, entry->idx_file_offset + sizeof(uint64_t));
+
+  if (res != lsm_error_ok) {
+    pthread_mutex_unlock(&store->idx.lock);
+
+    return res;
+  }
+
+  uint64_t val = 0;
+  res = lsm_fwrite(NULL, store->idx.f, sizeof(uint64_t), 1, &val);
+
+  pthread_mutex_unlock(&store->idx.lock);
+
+  if (res != lsm_error_ok) {
+    return res;
+  }
+
+  fflush(store->idx.f);
+
+  // Remove data file if present
+  if (entry->data_len > 0) {
+    if (handle->f != NULL) {
+      fclose(handle->f);
+      handle->f = NULL;
+    }
+
+    char data_path[lsm_entry_data_path_len(handle) + 1];
+    lsm_entry_data_path(data_path, handle);
+
+    if (remove(data_path) != 0) {
+      return lsm_error_failed_io;
+    }
+  }
+
+  return lsm_error_ok;
+}

lsm/src/store/lsm_store_entry.c

@@ -19,6 +19,14 @@ lsm_error lsm_entry_init(lsm_entry **ptr) {
   return lsm_error_ok;
 }
 
+void lsm_entry_free(lsm_entry *entry) {
+  if (entry->attrs.count > 0) {
+    free(entry->attrs.items);
+  }
+
+  free(entry);
+}
+
 lsm_error lsm_entry_wrapper_init(lsm_entry_wrapper **ptr) {
   lsm_entry_wrapper *wrap = calloc(1, sizeof(lsm_entry_wrapper));
 
@@ -58,7 +66,10 @@ void lsm_entry_close(lsm_entry_handle *handle) {
     lsm_entry_disk_insert(handle);
   } else if ((handle->states & lsm_entry_handle_state_removed) &&
              !(handle->states & lsm_entry_handle_state_new)) {
-    /* lsm_entry_disk_remove(handle); */
+    lsm_entry_disk_remove(handle);
+
+    lsm_entry_free(handle->wrapper->entry);
+    handle->wrapper->entry = NULL;
   } else if (handle->states & lsm_entry_handle_state_updated) {
     /* lsm_entry_disk_update(handle); */
   }
@@ -216,3 +227,25 @@ lsm_error lsm_entry_attr_insert_uint8_t(lsm_entry_handle *handle, uint8_t type,
 uint64_t lsm_entry_data_len(lsm_entry_handle *handle) {
   return handle->wrapper->entry->data_len;
 }
+
+uint64_t lsm_entry_data_path_len(lsm_entry_handle *handle) {
+  // [data path]/[entry key][data file suffix]
+  return lsm_str_len(handle->store->data_path) +
+         lsm_str_len(handle->wrapper->entry->key) +
+         strlen(LSM_DATA_FILE_SUFFIX) + 1;
+}
+void lsm_entry_data_path(char *buf, lsm_entry_handle *handle) {
+  lsm_str *data_path = handle->store->data_path;
+  lsm_str *key = handle->wrapper->entry->key;
+
+  memcpy(buf, lsm_str_ptr(data_path), lsm_str_len(data_path));
+
+  uint64_t index = lsm_str_len(data_path);
+  buf[index] = '/';
+
+  index += 1;
+  memcpy(&buf[index], lsm_str_ptr(key), lsm_str_len(key));
+
+  index += lsm_str_len(key);
+  strcpy(&buf[index], LSM_DATA_FILE_SUFFIX);
+}

src/lander/lander.c

@@ -19,6 +19,14 @@ http_route lander_routes[] = {
         .steps_res = {http_loop_step_write_header, lander_stream_body_to_client,
                       NULL},
     },
+    {
+        .type = http_route_regex,
+        .method = http_delete,
+        .path = "^/([^/]+)$",
+        .steps = {http_loop_step_auth, lander_remove_entry, NULL},
+        .steps_res = {http_loop_step_write_header, http_loop_step_write_body,
+                      NULL},
+    },
     {
         .type = http_route_regex,
         .method = http_post,

src/lander/lander_delete.c

@@ -0,0 +1,29 @@
+#include "lander.h"
+
+bool lander_remove_entry(event_loop_conn *conn) {
+  http_loop_ctx *ctx = conn->ctx;
+  lander_ctx *c_ctx = ctx->c;
+  http_loop_gctx *gctx = ctx->g;
+  lander_gctx *c_gctx = gctx->c;
+
+  const char *key_s = &ctx->req.path[ctx->req.regex_groups[1].rm_so];
+  int key_len = ctx->req.regex_groups[1].rm_eo - ctx->req.regex_groups[1].rm_so;
+
+  lsm_str *key;
+  lsm_str_init_copy_n(&key, (char *)key_s, key_len);
+
+  switch (lsm_store_open_write(&c_ctx->entry, c_gctx->store, key)) {
+  case lsm_error_ok:
+    break;
+  case lsm_error_not_found:
+    ctx->res.status = http_not_found;
+    return true;
+  default:
+    ctx->res.status = http_internal_server_error;
+    return true;
+  }
+
+  lsm_entry_remove(c_ctx->entry);
+
+  return true;
+}