chore: Improve binding for waku_sync (#3102)

Author: darshankabariya

vendor/negentropy

@@ -67,6 +67,8 @@ proc toBufferSeq(buffLen: uint, buffPtr: ptr Buffer): seq[Buffer] =
 
 type NegentropyStorage* = distinct pointer
 
+proc get_last_error(): cstring {.header: NEGENTROPY_HEADER, importc: "get_last_error".}
+
 # https://github.com/waku-org/negentropy/blob/d4845b95b5a2d9bee28555833e7502db71bf319f/cpp/negentropy_wrapper.h#L27
 proc storage_init(
   db_path: cstring, name: cstring
@@ -194,6 +196,10 @@ proc new*(T: type NegentropyStorage): Result[T, string] =
   #[ TODO: Uncomment once we move to lmdb
   if storage == nil:
     return err("storage initialization failed") ]#
+
+  if storage == nil:
+    return err($get_last_error())
+
   return ok(storage)
 
 proc delete*(storage: NegentropyStorage) =
@@ -211,7 +217,7 @@ proc erase*(
   if res:
     return ok()
   else:
-    return err("erase error")
+    return err($get_last_error())
 
 proc insert*(
     storage: NegentropyStorage, id: int64, hash: WakuMessageHash
@@ -225,7 +231,7 @@ proc insert*(
   if res:
     return ok()
   else:
-    return err("insert error")
+    return err($get_last_error())
 
 proc len*(storage: NegentropyStorage): int =
   int(storage.size)
@@ -245,6 +251,10 @@ proc new*(
   #[ TODO: Uncomment once we move to lmdb
   if storage == nil:
     return err("storage initialization failed") ]#
+
+  if subrange == nil:
+    return err($get_last_error())
+
   return ok(subrange)
 
 proc delete*(subrange: NegentropySubRangeStorage) =
@@ -296,16 +306,20 @@ proc new*(
     let raw_negentropy =
       constructNegentropy(NegentropyStorage(storage), uint64(frameSizeLimit))
 
-    let negentropy = NegentropyWithStorage(inner: raw_negentropy)
+    if cast[pointer](raw_negentropy) == nil:
+      return err($get_last_error())
 
+    let negentropy = NegentropyWithStorage(inner: raw_negentropy)
     return ok(negentropy)
   elif storage is NegentropySubRangeStorage:
     let raw_negentropy = constructNegentropyWithSubRange(
       NegentropySubRangeStorage(storage), uint64(frameSizeLimit)
     )
 
-    let negentropy = NegentropyWithSubRange(inner: raw_negentropy)
+    if cast[pointer](raw_negentropy) == nil:
+      return err($get_last_error())
 
+    let negentropy = NegentropyWithSubRange(inner: raw_negentropy)
     return ok(negentropy)
 
 method delete*(self: NegentropyWithSubRange) =
@@ -319,7 +333,7 @@ method initiate*(self: NegentropyWithSubRange): Result[NegentropyPayload, string
   let ret = self.inner.raw_initiate_subrange(myResultPtr)
   if ret < 0 or myResultPtr == nil:
     error "negentropy initiate failed with code ", code = ret
-    return err("negentropy already initiated!")
+    return err($get_last_error())
   let bytes: seq[byte] = bufferToBytes(addr(myResultPtr.output))
   free_result(myResultPtr)
   trace "received return from initiate", len = myResultPtr.output.len
@@ -340,7 +354,7 @@ method serverReconcile*(
   let ret = self.inner.raw_reconcile_subrange(queryBufPtr, myResultPtr)
   if ret < 0:
     error "raw_reconcile failed with code ", code = ret
-    return err($myResultPtr.error)
+    return err($get_last_error())
   trace "received return from raw_reconcile", len = myResultPtr.output.len
 
   let outputBytes: seq[byte] = bufferToBytes(addr(myResultPtr.output))
@@ -368,7 +382,7 @@ method clientReconcile*(
   let ret = self.inner.raw_reconcile_with_ids_subrange(cQuery.unsafeAddr, myResultPtr)
   if ret < 0:
     error "raw_reconcile failed with code ", code = ret
-    return err($myResultPtr.error)
+    return err($get_last_error())
 
   let output = bufferToBytes(addr myResult.output)
 
@@ -414,7 +428,7 @@ method initiate*(self: NegentropyWithStorage): Result[NegentropyPayload, string]
   let ret = self.inner.raw_initiate(myResultPtr)
   if ret < 0 or myResultPtr == nil:
     error "negentropy initiate failed with code ", code = ret
-    return err("negentropy already initiated!")
+    return err($get_last_error())
   let bytes: seq[byte] = bufferToBytes(addr(myResultPtr.output))
   free_result(myResultPtr)
   trace "received return from initiate", len = myResultPtr.output.len
@@ -435,7 +449,7 @@ method serverReconcile*(
   let ret = self.inner.raw_reconcile(queryBufPtr, myResultPtr)
   if ret < 0:
     error "raw_reconcile failed with code ", code = ret
-    return err($myResultPtr.error)
+    return err($get_last_error())
   trace "received return from raw_reconcile", len = myResultPtr.output.len
 
   let outputBytes: seq[byte] = bufferToBytes(addr(myResultPtr.output))
@@ -463,7 +477,7 @@ method clientReconcile*(
   let ret = self.inner.raw_reconcile_with_ids(cQuery.unsafeAddr, myResultPtr)
   if ret < 0:
     error "raw_reconcile failed with code ", code = ret
-    return err($myResultPtr.error)
+    return err($get_last_error())
 
   let output = bufferToBytes(addr myResult.output)