removed unused files and added IDFromTimestamp function

Signed-off-by: Utkarsh Srivastava <srivastavautkarsh8097@gmail.com>

Author: tangledbytes

binding.gyp

@@ -5,7 +5,6 @@
         "cflags_cc!": [ "-fno-exceptions" ],
         "sources": [
             "cppsrc/main.cpp",
-            "cppsrc/generate_hash.cpp"
         ],
         "cflags_cc": [
             "-std=c++17"

cppsrc/main.cpp

@@ -61,12 +61,21 @@ class Snowflake : public Napi::ObjectWrap<Snowflake>
     Napi::Value getUniqueIDBigInt(const Napi::CallbackInfo &info);
     Napi::Value getTimestampFromID(const Napi::CallbackInfo &info);
     Napi::Value getNodeIDFomID(const Napi::CallbackInfo &info);
+    Napi::Value getIDFromTimestamp(const Napi::CallbackInfo &info);
 };
 
 Napi::Object Snowflake::Init(Napi::Env env, Napi::Object exports)
 {
     // This method is used to hook the accessor and method callbacks
-    auto func = DefineClass(env, "Snowflake", {InstanceMethod("getUniqueID", &Snowflake::getUniqueIDBigInt), InstanceMethod("getTimestampFromID", &Snowflake::getTimestampFromID), InstanceMethod("getNodeIDFromID", &Snowflake::getNodeIDFomID)});
+    auto func = DefineClass(
+        env,
+        "Snowflake",
+        {
+            InstanceMethod("getUniqueID", &Snowflake::getUniqueIDBigInt),
+            InstanceMethod("getTimestampFromID", &Snowflake::getTimestampFromID),
+            InstanceMethod("getNodeIDFromID", &Snowflake::getNodeIDFomID),
+            InstanceMethod("getIDFromTimestamp", &Snowflake::getIDFromTimestamp),
+        });
 
     // Create a peristent reference to the class constructor. This will allow
     // a function called on a class prototype and a function
@@ -152,13 +161,14 @@ Napi::Value Snowflake::getTimestampFromID(const Napi::CallbackInfo &info)
 
         uniqueID = std::stoull(first.Utf8Value());
     }
-    else if (info[0].IsNumber())
+    else if (info[0].IsBigInt())
     {
-        uniqueID = info[0].As<Napi::Number>().Int64Value();
+        bool lossless = true;
+        uniqueID = info[0].As<Napi::BigInt>().Int64Value(&lossless);
     }
     else
     {
-        Napi::TypeError::New(env, "Number or string expected").ThrowAsJavaScriptException();
+        Napi::TypeError::New(env, "BigInt or string expected").ThrowAsJavaScriptException();
     }
 
     uint64_t timestamp = uniqueID >> (TOTAL_BITS - EPOCH_BITS);
@@ -167,9 +177,7 @@ Napi::Value Snowflake::getTimestampFromID(const Napi::CallbackInfo &info)
 }
 
 /**
- * Returns timestamp at which the id was generated by retreiving
- * the first 42 bits of the id, which are filled with current timestamp
- * bits
+ * Returns NodeID/Machine ID at which the id was generated
 */
 Napi::Value Snowflake::getNodeIDFomID(const Napi::CallbackInfo &info)
 {
@@ -182,13 +190,14 @@ Napi::Value Snowflake::getNodeIDFomID(const Napi::CallbackInfo &info)
 
         uniqueID = std::stoull(first.Utf8Value());
     }
-    else if (info[0].IsNumber())
+    else if (info[0].IsBigInt())
     {
-        uniqueID = info[0].As<Napi::Number>().Int64Value();
+        bool lossless = true;
+        uniqueID = info[0].As<Napi::BigInt>().Int64Value(&lossless);
     }
     else
     {
-        Napi::TypeError::New(env, "Number or string expected").ThrowAsJavaScriptException();
+        Napi::TypeError::New(env, "BigInt or string expected").ThrowAsJavaScriptException();
     }
 
     int BITS = TOTAL_BITS - NODE_ID_BITS - SEQUENCE_BITS;
@@ -197,6 +206,39 @@ Napi::Value Snowflake::getNodeIDFomID(const Napi::CallbackInfo &info)
     return Napi::Number::New(env, machineID);
 }
 
+/**
+ * getIDFromTimestamp takes in a timestamp and will produce
+ * id corresponding to that timestamp. It will generate ID with
+ * sequence number 0.
+ * 
+ * This method can be useful in writing SQL queries 
+ * where you want results which were created after
+ * a certain timestamp
+*/
+Napi::Value Snowflake::getIDFromTimestamp(const Napi::CallbackInfo &info)
+{
+    auto env = info.Env();
+    uint64_t timestamp = 0;
+
+    if (info[0].IsString())
+    {
+        auto first = info[0].As<Napi::String>();
+        timestamp = std::stoull(first.Utf8Value());
+    }
+    else if (info[0].IsNumber())
+    {
+        timestamp = info[0].As<Napi::Number>().Int64Value();
+    }
+
+    uint64_t currentTimestamp = timestamp - this->_CUSTOM_EPOCH;
+
+    uint64_t id{};
+    id = currentTimestamp << (TOTAL_BITS - EPOCH_BITS);
+    id |= (this->_nodeID << (TOTAL_BITS - EPOCH_BITS - NODE_ID_BITS));
+
+    return Napi::BigInt::New(env, id);
+}
+
 // ////////////////////////////////////////////////////////////////////////////////////////
 
 Napi::Object InitAll(Napi::Env env, Napi::Object exports)