repo_description: 🦔 Fast, lightweight & schema-less search backend. An alternative to Elasticsearch that runs on a few MBs of RAM.
repo_topics: backend database graph index infrastructure rust search search-engine search-server server
code: // Sonic
  //
  // Fast, lightweight and schema-less search backend
  // Copyright: 2019, Valerian Saliou <[REDACTED_EMAIL]>
  // License: Mozilla Public License v2.0 (MPL v2.0)
  
  use crate::store::fst::StoreFSTPool;
  use crate::store::fst::{StoreFSTActionBuilder, StoreFSTMisc};
  use crate::store::item::StoreItem;
  use crate::store::kv::StoreKVActionBuilder;
  use crate::store::kv::{StoreKVAcquireMode, StoreKVPool};
  
  pub struct ExecutorCount;
  
  impl ExecutorCount {
      pub fn execute(store: StoreItem) -> Result<u32, ()> {
          match store {
              // Count terms in (collection, bucket, object) from KV
              StoreItem(collection, Some(bucket), Some(object)) => {
                  // Important: acquire database access read lock, and reference it in context. This \
                  //   prevents the database from being erased while using it in this block.
                  general_kv_access_lock_read!();
  
                  if let Ok(kv_store) = StoreKVPool::acquire(StoreKVAcquireMode::OpenOnly, collection)
                  {
                      // Important: acquire bucket store read lock
                      executor_kv_lock_read!(kv_store);
  
                      let kv_action = StoreKVActionBuilder::access(bucket, kv_store);
  
                      // Try to resolve existing OID to IID
                      let oid = object.as_str();
  
                      kv_action
                          .get_oid_to_iid(oid)
                          .unwrap_or(None)
                          .map(|iid| {
                              // List terms for IID
                              if let Some(terms) = kv_action.get_iid_to_terms(iid).unwrap_or(None) {
                                  terms.len() as u32
                              } else {
                                  0
                              }
                          })
                          .ok_or(())
                          .or(Ok(0))
                  } else {
                      Err(())
                  }
              }
              // Count terms in (collection, bucket) from FST
              StoreItem(collection, Some(bucket), None) => {
                  // Important: acquire graph access read lock, and reference it in context. This \
                  //   prevents the graph from being erased while using it in this block.
                  general_fst_access_lock_read!();
  
                  if let Ok(fst_store) = StoreFSTPool::acquire(collection, bucket) {
                      let fst_action = StoreFSTActionBuilder::access(fst_store);
  
                      Ok(fst_action.count_words() as u32)
                  } else {
                      Err(())
                  }
              }
              // Count buckets in (collection) from FS
              StoreItem(collection, None, None) => {
                  StoreFSTMisc::count_collection_buckets(collection).map(|count| count as u32)
              }
              _ => Err(()),
          }
      }
  }
  