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Fixed LookupByKey for Java & C#

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Change-Id: I05c02223675dee241d1ae8cb466e5186444058c8
Tested: on Linux.
This commit is contained in:
Wouter van Oortmerssen
2017-05-08 18:24:47 -07:00
parent 0920d663d5
commit 8468ea1ab4
6 changed files with 62 additions and 46 deletions
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17
docs/source/JavaCsharpUsage.md
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@@ -147,19 +147,20 @@ To use it:
array.
- Instead of calling standard generated method,
e.g.: `Monster.createTestarrayoftablesVector`,
call `CreateMySortedVectorOfTables` in C# or
call `CreateSortedVectorOfMonster` in C# or
`createSortedVectorOfTables` (from the `FlatBufferBuilder` object) in Java,
which will first sort all offsets such that the tables they refer to
are sorted by the key field, then serialize it.
- Now when you're accessing the FlatBuffer, you can use `LookupByKey`
to access elements of the vector, e.g.:
`Monster.lookupByKey(tablesVectorOffset, "Frodo", dataBuffer)`,
- Now when you're accessing the FlatBuffer, you can use
the `ByKey` accessor to access elements of the vector, e.g.:
`monster.testarrayoftablesByKey("Frodo")` in Java or
`monster.TestarrayoftablesByKey("Frodo")` in C#,
which returns an object of the corresponding table type,
or `null` if not found.
`LookupByKey` performs a binary search, so should have a similar speed to
`Dictionary`, though may be faster because of better caching. `LookupByKey`
only works if the vector has been sorted, it will likely not find elements
if it hasn't been sorted.
`ByKey` performs a binary search, so should have a similar
speed to `Dictionary`, though may be faster because of better caching.
`ByKey` only works if the vector has been sorted, it will
likely not find elements if it hasn't been sorted.
## Text parsing

35
src/idl_gen_general.cpp
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@@ -1005,6 +1005,26 @@ void GenStruct(StructDef &struct_def, std::string *code_ptr) {
code += lang_.accessor_prefix + "__vector_len(o) : 0; ";
code += lang_.getter_suffix;
code += "}\n";
// See if we should generate a by-key accessor.
if (field.value.type.element == BASE_TYPE_STRUCT &&
!field.value.type.struct_def->fixed) {
auto &sd = *field.value.type.struct_def;
auto &fields = sd.fields.vec;
for (auto kit = fields.begin(); kit != fields.end(); ++kit) {
auto &key_field = **kit;
if (key_field.key) {
code += " public " + sd.name + lang_.optional_suffix + " ";
code += MakeCamel(field.name, lang_.first_camel_upper) + "ByKey(";
code += GenTypeNameDest(key_field.value.type) + " key)";
code += offset_prefix;
code += sd.name + ".__lookup_by_key(";
code += lang_.accessor_prefix + "__vector(o), key, ";
code += lang_.accessor_prefix + "bb) : null; ";
code += "}\n";
break;
}
}
}
}
// Generate a ByteBuffer accessor for strings & vectors of scalars.
if ((field.value.type.base_type == BASE_TYPE_VECTOR &&
@@ -1302,7 +1322,8 @@ void GenStruct(StructDef &struct_def, std::string *code_ptr) {
}
else {
code += "\n public static VectorOffset ";
code += "CreateMySortedVectorOfTables(FlatBufferBuilder builder, ";
code += "CreateSortedVectorOf" + struct_def.name;
code += "(FlatBufferBuilder builder, ";
code += "Offset<" + struct_def.name + ">";
code += "[] offsets) {\n";
code += " Array.Sort(offsets, (Offset<" + struct_def.name +
@@ -1312,8 +1333,8 @@ void GenStruct(StructDef &struct_def, std::string *code_ptr) {
}
code += "\n public static " + struct_def.name + lang_.optional_suffix;
code += " " + FunctionStart('L') + "ookupByKey(" + GenVectorOffsetType();
code += " vectorOffset, " + GenTypeNameDest(key_field->value.type);
code += " __lookup_by_key(int vectorLocation, ";
code += GenTypeNameDest(key_field->value.type);
code += " key, ByteBuffer bb) {\n";
if (key_field->value.type.base_type == BASE_TYPE_STRING) {
code += " byte[] byteKey = ";
@@ -1322,13 +1343,9 @@ void GenStruct(StructDef &struct_def, std::string *code_ptr) {
else
code += "System.Text.Encoding.UTF8.GetBytes(key);\n";
}
code += " int vectorLocation = " + GenByteBufferLength("bb");
code += " - vectorOffset";
if (lang_.language == IDLOptions::kCSharp) code += ".Value";
code += ";\n int span = ";
code += "bb." + FunctionStart('G') + "etInt(vectorLocation);\n";
code += " int span = ";
code += "bb." + FunctionStart('G') + "etInt(vectorLocation - 4);\n";
code += " int start = 0;\n";
code += " vectorLocation += 4;\n";
code += " while (span != 0) {\n";
code += " int middle = span / 2;\n";
code += GenLookupKeyGetter(key_field);

8
tests/FlatBuffers.Test/FlatBuffersExampleTests.cs
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@@ -50,7 +50,7 @@ namespace FlatBuffers.Test
Monster.StartMonster(fbb);
Monster.AddName(fbb, names[2]);
off[2] = Monster.EndMonster(fbb);
var sortMons = Monster.CreateMySortedVectorOfTables(fbb, off);
var sortMons = Monster.CreateSortedVectorOfMonster(fbb, off);
// We set up the same values as monsterdata.json:
@@ -123,9 +123,9 @@ namespace FlatBuffers.Test
Assert.AreEqual(monster.Testarrayoftables(2).Value.Name, "Wilma");
// Example of searching for a table by the key
Assert.IsTrue(Monster.LookupByKey(sortMons, "Frodo", fbb.DataBuffer) != null);
Assert.IsTrue(Monster.LookupByKey(sortMons, "Barney", fbb.DataBuffer) != null);
Assert.IsTrue(Monster.LookupByKey(sortMons, "Wilma", fbb.DataBuffer)!= null);
Assert.IsTrue(monster.TestarrayoftablesByKey("Frodo") != null);
Assert.IsTrue(monster.TestarrayoftablesByKey("Barney") != null);
Assert.IsTrue(monster.TestarrayoftablesByKey("Wilma") != null);
// testType is an existing field and mutating it should succeed
Assert.AreEqual(monster.TestType, Any.Monster);

32
tests/JavaTest.java
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@@ -63,7 +63,7 @@ class JavaTest {
Monster.addName(fbb, names[2]);
off[2] = Monster.endMonster(fbb);
int sortMons = fbb.createSortedVectorOfTables(new Monster(), off);
// We set up the same values as monsterdata.json:
int str = fbb.createString("MyMonster");
@@ -135,16 +135,16 @@ class JavaTest {
// the mana field should retain its default value
TestEq(monster.mutateMana((short)10), false);
TestEq(monster.mana(), (short)150);
// Accessing a vector of sorted by the key tables
TestEq(monster.testarrayoftables(0).name(), "Barney");
TestEq(monster.testarrayoftables(1).name(), "Frodo");
TestEq(monster.testarrayoftables(2).name(), "Wilma");
// Example of searching for a table by the key
TestEq(Monster.lookupByKey(sortMons, "Frodo", fbb.dataBuffer()).name(), "Frodo");
TestEq(Monster.lookupByKey(sortMons, "Barney", fbb.dataBuffer()).name(), "Barney");
TestEq(Monster.lookupByKey(sortMons, "Wilma", fbb.dataBuffer()).name(), "Wilma");
TestEq(monster.testarrayoftablesByKey("Frodo").name(), "Frodo");
TestEq(monster.testarrayoftablesByKey("Barney").name(), "Barney");
TestEq(monster.testarrayoftablesByKey("Wilma").name(), "Wilma");
// testType is an existing field and mutating it should succeed
TestEq(monster.testType(), (byte)Any.Monster);
@@ -201,7 +201,7 @@ class JavaTest {
static void TestBuffer(ByteBuffer bb) {
TestEq(Monster.MonsterBufferHasIdentifier(bb), true);
Monster monster = Monster.getRootAsMonster(bb);
TestEq(monster.hp(), (short)80);
@@ -259,25 +259,25 @@ class JavaTest {
TestEq(monster.testhashu32Fnv1(), Integer.MAX_VALUE + 1L);
}
static void TestNamespaceNesting() {
// reference / manipulate these to verify compilation
FlatBufferBuilder fbb = new FlatBufferBuilder(1);
TableInNestedNS.startTableInNestedNS(fbb);
TableInNestedNS.addFoo(fbb, 1234);
int nestedTableOff = TableInNestedNS.endTableInNestedNS(fbb);
TableInFirstNS.startTableInFirstNS(fbb);
TableInFirstNS.startTableInFirstNS(fbb);
TableInFirstNS.addFooTable(fbb, nestedTableOff);
int off = TableInFirstNS.endTableInFirstNS(fbb);
}
static void TestNestedFlatBuffer() {
final String nestedMonsterName = "NestedMonsterName";
final short nestedMonsterHp = 600;
final short nestedMonsterMana = 1024;
FlatBufferBuilder fbb1 = new FlatBufferBuilder(16);
int str1 = fbb1.createString(nestedMonsterName);
Monster.startMonster(fbb1);
@@ -288,8 +288,8 @@ class JavaTest {
Monster.finishMonsterBuffer(fbb1, monster1);
byte[] fbb1Bytes = fbb1.sizedByteArray();
fbb1 = null;
FlatBufferBuilder fbb2 = new FlatBufferBuilder(16);
FlatBufferBuilder fbb2 = new FlatBufferBuilder(16);
int str2 = fbb2.createString("My Monster");
int nestedBuffer = Monster.createTestnestedflatbufferVector(fbb2, fbb1Bytes);
Monster.startMonster(fbb2);
@@ -299,7 +299,7 @@ class JavaTest {
Monster.addTestnestedflatbuffer(fbb2, nestedBuffer);
int monster = Monster.endMonster(fbb2);
Monster.finishMonsterBuffer(fbb2, monster);
// Now test the data extracted from the nested buffer
Monster mons = Monster.getRootAsMonster(fbb2.dataBuffer());
Monster nestedMonster = mons.testnestedflatbufferAsMonster();

9
tests/MyGame/Example/Monster.cs
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@@ -41,6 +41,7 @@ public struct Monster : IFlatbufferObject
/// multiline too
public Monster? Testarrayoftables(int j) { int o = __p.__offset(26); return o != 0 ? (Monster?)(new Monster()).__assign(__p.__indirect(__p.__vector(o) + j * 4), __p.bb) : null; }
public int TestarrayoftablesLength { get { int o = __p.__offset(26); return o != 0 ? __p.__vector_len(o) : 0; } }
public Monster? TestarrayoftablesByKey(string key) { int o = __p.__offset(26); return o != 0 ? Monster.__lookup_by_key(__p.__vector(o), key, __p.bb) : null; }
public Monster? Enemy { get { int o = __p.__offset(28); return o != 0 ? (Monster?)(new Monster()).__assign(__p.__indirect(o + __p.bb_pos), __p.bb) : null; } }
public byte Testnestedflatbuffer(int j) { int o = __p.__offset(30); return o != 0 ? __p.bb.Get(__p.__vector(o) + j * 1) : (byte)0; }
public int TestnestedflatbufferLength { get { int o = __p.__offset(30); return o != 0 ? __p.__vector_len(o) : 0; } }
@@ -132,17 +133,15 @@ public struct Monster : IFlatbufferObject
}
public static void FinishMonsterBuffer(FlatBufferBuilder builder, Offset<Monster> offset) { builder.Finish(offset.Value, "MONS"); }
public static VectorOffset CreateMySortedVectorOfTables(FlatBufferBuilder builder, Offset<Monster>[] offsets) {
public static VectorOffset CreateSortedVectorOfMonster(FlatBufferBuilder builder, Offset<Monster>[] offsets) {
Array.Sort(offsets, (Offset<Monster> o1, Offset<Monster> o2) => Table.CompareStrings(Table.__offset(10, o1.Value, builder.DataBuffer), Table.__offset(10, o2.Value, builder.DataBuffer), builder.DataBuffer));
return builder.CreateVectorOfTables(offsets);
}
public static Monster? LookupByKey(VectorOffset vectorOffset, string key, ByteBuffer bb) {
public static Monster? __lookup_by_key(int vectorLocation, string key, ByteBuffer bb) {
byte[] byteKey = System.Text.Encoding.UTF8.GetBytes(key);
int vectorLocation = bb.Length - vectorOffset.Value;
int span = bb.GetInt(vectorLocation);
int span = bb.GetInt(vectorLocation - 4);
int start = 0;
vectorLocation += 4;
while (span != 0) {
int middle = span / 2;
int tableOffset = Table.__indirect(vectorLocation + 4 * (start + middle), bb);

7
tests/MyGame/Example/Monster.java
View File

@@ -47,6 +47,7 @@ public final class Monster extends Table {
public Monster testarrayoftables(int j) { return testarrayoftables(new Monster(), j); }
public Monster testarrayoftables(Monster obj, int j) { int o = __offset(26); return o != 0 ? obj.__assign(__indirect(__vector(o) + j * 4), bb) : null; }
public int testarrayoftablesLength() { int o = __offset(26); return o != 0 ? __vector_len(o) : 0; }
public Monster testarrayoftablesByKey(String key) { int o = __offset(26); return o != 0 ? Monster.__lookup_by_key(__vector(o), key, bb) : null; }
public Monster enemy() { return enemy(new Monster()); }
public Monster enemy(Monster obj) { int o = __offset(28); return o != 0 ? obj.__assign(__indirect(o + bb_pos), bb) : null; }
public int testnestedflatbuffer(int j) { int o = __offset(30); return o != 0 ? bb.get(__vector(o) + j * 1) & 0xFF : 0; }
@@ -145,12 +146,10 @@ public final class Monster extends Table {
@Override
protected int keysCompare(Integer o1, Integer o2, ByteBuffer _bb) { return compareStrings(__offset(10, o1, _bb), __offset(10, o2, _bb), _bb); }
public static Monster lookupByKey(int vectorOffset, String key, ByteBuffer bb) {
public static Monster __lookup_by_key(int vectorLocation, String key, ByteBuffer bb) {
byte[] byteKey = key.getBytes(Table.UTF8_CHARSET.get());
int vectorLocation = bb.array().length - vectorOffset;
int span = bb.getInt(vectorLocation);
int span = bb.getInt(vectorLocation - 4);
int start = 0;
vectorLocation += 4;
while (span != 0) {
int middle = span / 2;
int tableOffset = __indirect(vectorLocation + 4 * (start + middle), bb);