[C#] Rework how sorted vectors are looked up (#7441)

This commit is contained in:
Derek Bailey
2022-08-15 09:33:07 -07:00
committed by GitHub
parent 44a7dc9995
commit 214125e417
5 changed files with 104 additions and 68 deletions

View File

@@ -459,20 +459,24 @@ class CSharpGenerator : public BaseGenerator {
}
}
std::string GetObjectConstructor(flatbuffers::StructDef &struct_def,
const std::string &data_buffer,
const std::string &offset) const {
// Use the generated type directly, to properly handle default values that
// might not be written to the buffer.
return "new " + Name(struct_def) + "().__assign(" + offset + ", " +
data_buffer + ")";
}
// Returns the function name that is able to read a value of the given type.
std::string GenGetterForLookupByKey(flatbuffers::FieldDef *key_field,
std::string GenGetterForLookupByKey(flatbuffers::StructDef &struct_def,
flatbuffers::FieldDef *key_field,
const std::string &data_buffer,
const char *num = nullptr) const {
auto type = key_field->value.type;
auto dest_mask = "";
auto dest_cast = DestinationCast(type);
auto getter = data_buffer + ".Get";
if (GenTypeBasic(type, false) != "byte") {
getter += ConvertCase(GenTypeBasic(type, false), Case::kUpperCamel);
}
getter = dest_cast + getter + "(" + GenOffsetGetter(key_field, num) + ")" +
dest_mask;
return getter;
const std::string &offset) const {
// Use the generated type directly, to properly handle default values that
// might not be written to the buffer.
return GetObjectConstructor(struct_def, data_buffer, offset) + "." +
Name(*key_field);
}
// Direct mutation is only allowed for scalar fields.
@@ -605,37 +609,15 @@ class CSharpGenerator : public BaseGenerator {
return key_offset;
}
std::string GenLookupKeyGetter(flatbuffers::FieldDef *key_field) const {
std::string key_getter = " ";
key_getter += "int tableOffset = Table.";
key_getter += "__indirect(vectorLocation + 4 * (start + middle)";
key_getter += ", bb);\n ";
if (IsString(key_field->value.type)) {
key_getter += "int comp = Table.";
key_getter += "CompareStrings(";
key_getter += GenOffsetGetter(key_field);
key_getter += ", byteKey, bb);\n";
} else {
auto get_val = GenGetterForLookupByKey(key_field, "bb");
key_getter += "int comp = " + get_val + ".CompareTo(key);\n";
}
return key_getter;
}
std::string GenKeyGetter(flatbuffers::FieldDef *key_field) const {
std::string key_getter = "";
auto data_buffer = "builder.DataBuffer";
if (IsString(key_field->value.type)) {
key_getter += "Table.CompareStrings(";
key_getter += GenOffsetGetter(key_field, "o1") + ", ";
key_getter += GenOffsetGetter(key_field, "o2") + ", " + data_buffer + ")";
} else {
auto field_getter = GenGetterForLookupByKey(key_field, data_buffer, "o1");
key_getter += field_getter;
field_getter = GenGetterForLookupByKey(key_field, data_buffer, "o2");
key_getter += ".CompareTo(" + field_getter + ")";
}
return key_getter;
std::string GenKeyGetter(flatbuffers::StructDef &struct_def,
flatbuffers::FieldDef *key_field) const {
// Get the getter for the key of the struct.
return GenGetterForLookupByKey(struct_def, key_field, "builder.DataBuffer",
"builder.DataBuffer.Length - o1.Value") +
".CompareTo(" +
GenGetterForLookupByKey(struct_def, key_field, "builder.DataBuffer",
"builder.DataBuffer.Length - o2.Value") +
")";
}
void GenStruct(StructDef &struct_def, std::string *code_ptr,
@@ -1240,7 +1222,8 @@ class CSharpGenerator : public BaseGenerator {
code += "); return ";
code += "builder.EndVector(); }\n";
// add Create...VectorBlock() overloads for T[], ArraySegment<T> and IntPtr
// add Create...VectorBlock() overloads for T[], ArraySegment<T> and
// IntPtr
code += " public static VectorOffset ";
code += "Create";
code += Name(field);
@@ -1269,7 +1252,8 @@ class CSharpGenerator : public BaseGenerator {
code += "VectorBlock(FlatBufferBuilder builder, ";
code += "IntPtr dataPtr, int sizeInBytes) ";
code += "{ builder.StartVector(1, sizeInBytes, 1); ";
code += "builder.Add<" + GenTypeBasic(vector_type) + ">(dataPtr, sizeInBytes); return builder.EndVector(); }\n";
code += "builder.Add<" + GenTypeBasic(vector_type) +
">(dataPtr, sizeInBytes); return builder.EndVector(); }\n";
}
// Generate a method to start a vector, data to be added manually
// after.
@@ -1322,9 +1306,10 @@ class CSharpGenerator : public BaseGenerator {
code += "(FlatBufferBuilder builder, ";
code += "Offset<" + struct_def.name + ">";
code += "[] offsets) {\n";
code += " Array.Sort(offsets, (Offset<" + struct_def.name +
"> o1, Offset<" + struct_def.name + "> o2) => " +
GenKeyGetter(key_field);
code += " Array.Sort(offsets,\n";
code += " (Offset<" + struct_def.name +
"> o1, Offset<" + struct_def.name + "> o2) =>\n";
code += " "+ GenKeyGetter(struct_def, key_field);
code += ");\n";
code += " return builder.CreateVectorOfTables(offsets);\n }\n";
@@ -1333,16 +1318,20 @@ class CSharpGenerator : public BaseGenerator {
code += "int vectorLocation, ";
code += GenTypeGet(key_field->value.type);
code += " key, ByteBuffer bb) {\n";
if (IsString(key_field->value.type)) {
code += " byte[] byteKey = ";
code += "System.Text.Encoding.UTF8.GetBytes(key);\n";
}
code +=
" " + struct_def.name + " obj_ = new " + struct_def.name + "();\n";
code += " int span = ";
code += "bb.GetInt(vectorLocation - 4);\n";
code += " int start = 0;\n";
code += " while (span != 0) {\n";
code += " int middle = span / 2;\n";
code += GenLookupKeyGetter(key_field);
code +=
" int tableOffset = Table.__indirect(vectorLocation + 4 * "
"(start + middle), bb);\n";
code += " obj_.__assign(tableOffset, bb);\n";
code +=
" int comp = obj_." + Name(*key_field) + ".CompareTo(key);\n";
code += " if (comp > 0) {\n";
code += " span = middle;\n";
code += " } else if (comp < 0) {\n";
@@ -1350,9 +1339,7 @@ class CSharpGenerator : public BaseGenerator {
code += " start += middle;\n";
code += " span -= middle;\n";
code += " } else {\n";
code += " return ";
code += "new " + struct_def.name + "()";
code += ".__assign(tableOffset, bb);\n";
code += " return obj_;\n";
code += " }\n }\n";
code += " return null;\n";
code += " }\n";
@@ -1608,8 +1595,7 @@ class CSharpGenerator : public BaseGenerator {
}
code += NamespacedName(enum_def) + "Union();\n";
code += indent + varialbe_name + ".Type = this." + camel_name_short +
"Type" +
type_suffix + ";\n";
"Type" + type_suffix + ";\n";
code += indent + "switch (this." + camel_name_short + "Type" + type_suffix +
") {\n";
for (auto eit = enum_def.Vals().begin(); eit != enum_def.Vals().end();