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more parsing
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@lambdageek
lambdageek committed Apr 11, 2024
1 parent 355ac09 commit 6689c43
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Showing 2 changed files with 302 additions and 55 deletions.
242 changes: 194 additions & 48 deletions src/native/managed/cdacreader/src/ContractDescriptorParser.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -12,19 +12,27 @@ public partial class ContractDescriptorParser
{
public const string TypeDescriptorSizeSigil = "!";

public static CompactContractDescriptor? Parse(ReadOnlySpan<byte> json)
/// <summary>
/// Parses the "compact" representation of a contract descriptor.
/// </summary>
/// <remarks>
/// See data_descriptor.md for the format.
/// </remarks>
public static ContractDescriptor? ParseCompact(ReadOnlySpan<byte> json)
{
return JsonSerializer.Deserialize(json, ContractDescriptorContext.Default.CompactContractDescriptor);
return JsonSerializer.Deserialize(json, ContractDescriptorContext.Default.ContractDescriptor);
}

[JsonSerializable(typeof(CompactContractDescriptor))]
[JsonSerializable(typeof(ContractDescriptor))]
[JsonSerializable(typeof(int))]
[JsonSerializable(typeof(string))]
[JsonSerializable(typeof(Dictionary<string, int>))]
[JsonSerializable(typeof(Dictionary<string, TypeDescriptor>))]
[JsonSerializable(typeof(Dictionary<string, FieldDescriptor>))]
[JsonSerializable(typeof(Dictionary<string, GlobalDescriptor>))]
[JsonSerializable(typeof(TypeDescriptor))]
[JsonSerializable(typeof(FieldDescriptor))]
[JsonSerializable(typeof(GlobalDescriptor))]
[JsonSourceGenerationOptions(AllowTrailingCommas = true,
DictionaryKeyPolicy = JsonKnownNamingPolicy.Unspecified, // contracts, types and globals are case sensitive
PropertyNamingPolicy = JsonKnownNamingPolicy.CamelCase,
Expand All @@ -34,15 +42,15 @@ internal sealed partial class ContractDescriptorContext : JsonSerializerContext
{
}

public class CompactContractDescriptor
public class ContractDescriptor
{
public int? Version { get; set; }
public string? Baseline { get; set; }
public Dictionary<string, int>? Contracts { get; set; }

public Dictionary<string, TypeDescriptor>? Types { get; set; }

// TODO: globals
public Dictionary<string, GlobalDescriptor>? Globals { get; set; }

[JsonExtensionData]
public Dictionary<string, object?>? Extras { get; set; }
Expand All @@ -51,25 +59,35 @@ public class CompactContractDescriptor
[JsonConverter(typeof(TypeDescriptorConverter))]
public class TypeDescriptor
{
public uint Size { get; set; }
public uint? Size { get; set; }
public Dictionary<string, FieldDescriptor>? Fields { get; set; }
}

// TODO: compact format needs a custom converter
[JsonConverter(typeof(FieldDescriptorConverter))]
public class FieldDescriptor
{
public string? Type { get; set; }
public int Offset { get; set; }
}

[JsonConverter(typeof(GlobalDescriptorConverter))]
public class GlobalDescriptor
{
public string? Type { get; set; }
public ulong Value { get; set; }
public bool Indirect { get; set; }
}

internal sealed class TypeDescriptorConverter : JsonConverter<TypeDescriptor>
{
// Almost a normal dictionary converter except:
// 1. looks for a special key "!" to set the Size property
// 2. field names are property names, but treated case-sensitively
public override TypeDescriptor Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
{
if (reader.TokenType != JsonTokenType.StartObject)
throw new JsonException();
uint size = 0;
uint? size = null;
Dictionary<string, FieldDescriptor>? fields = new();
while (reader.Read())
{
Expand Down Expand Up @@ -97,6 +115,7 @@ public override TypeDescriptor Read(ref Utf8JsonReader reader, Type typeToConver
}
break;
case JsonTokenType.Comment:
// unexpected - we specified to skip comments. but let's ignore anyway
break;
default:
throw new JsonException();
Expand All @@ -113,60 +132,187 @@ public override void Write(Utf8JsonWriter writer, TypeDescriptor value, JsonSeri

internal sealed class FieldDescriptorConverter : JsonConverter<FieldDescriptor>
{
// Compact Field descriptors are either one or two element arrays
// 1. [number] - no type, offset is given as the number
// 2. [number, string] - has a type, offset is given as the number
public override FieldDescriptor Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
{
if (reader.TokenType == JsonTokenType.Number || reader.TokenType == JsonTokenType.String)
return new FieldDescriptor { Offset = reader.GetInt32() };
if (GetInt32FromToken(ref reader, out int offset))
return new FieldDescriptor { Offset = offset };
if (reader.TokenType != JsonTokenType.StartArray)
throw new JsonException();
int eltIdx = 0;
string? type = null;
int offset = 0;
while (reader.Read())
reader.Read();
// two cases:
// [number]
// ^ we're here
// or
// [number, string]
// ^ we're here
if (!GetInt32FromToken(ref reader, out offset))
throw new JsonException();
reader.Read(); // end of array or string
if (reader.TokenType == JsonTokenType.EndArray)
return new FieldDescriptor { Offset = offset };
if (reader.TokenType != JsonTokenType.String)
throw new JsonException();
string? type = reader.GetString();
reader.Read(); // end of array
if (reader.TokenType != JsonTokenType.EndArray)
throw new JsonException();
return new FieldDescriptor { Type = type, Offset = offset };
}

public override void Write(Utf8JsonWriter writer, FieldDescriptor value, JsonSerializerOptions options)
{
throw new NotImplementedException();
}
}

internal sealed class GlobalDescriptorConverter : JsonConverter<GlobalDescriptor>
{
public override GlobalDescriptor Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
{
// four cases:
// 1. number - no type, direct value, given value
// 2. [number] - no type, indirect value, given aux data ptr
// 3. [number, string] - type, direct value, given value
// 4. [[number], string] - type, indirect value, given aux data ptr

// Case 1: number
if (GetUInt64FromToken(ref reader, out ulong valueCase1))
return new GlobalDescriptor { Value = valueCase1 };
if (reader.TokenType != JsonTokenType.StartArray)
throw new JsonException();
reader.Read();
// we're in case 2 or 3 or 4
// case 2: [number]
// ^ we're here
// case 3: [number, string]
// ^ we're here
// case 4: [[number], string]
// ^ we're here
if (reader.TokenType == JsonTokenType.StartArray)
{
switch (reader.TokenType)
{
case JsonTokenType.EndArray:
return new FieldDescriptor { Type = type, Offset = offset };
case JsonTokenType.Comment:
// don't incrment eltIdx
continue;
default:
break;
}
switch (eltIdx)
// case 4: [[number], string]
// ^ we're here
reader.Read(); // number
if (!GetUInt64FromToken(ref reader, out ulong value))
throw new JsonException();
reader.Read(); // end of inner array
if (reader.TokenType != JsonTokenType.EndArray)
throw new JsonException();
reader.Read(); // string
if (reader.TokenType != JsonTokenType.String)
throw new JsonException();
string? type = reader.GetString();
reader.Read(); // end of outer array
if (reader.TokenType != JsonTokenType.EndArray)
throw new JsonException();
return new GlobalDescriptor { Type = type, Value = value, Indirect = true };
}
else
{
// case 2 or 3
// case 2: [number]
// ^ we're here
// case 3: [number, string]
// ^ we're here
if (!GetUInt64FromToken(ref reader, out ulong valueCase2or3))
throw new JsonException();
reader.Read(); // end of array (case 2) or string (case 3)
if (reader.TokenType == JsonTokenType.EndArray) // it was case 2
return new GlobalDescriptor { Value = valueCase2or3, Indirect = true };
else if (reader.TokenType == JsonTokenType.String) // it was case 3
{
case 0:
{
// expect an offset - either a string or a number token
if (reader.TokenType == JsonTokenType.Number || reader.TokenType == JsonTokenType.String)
offset = reader.GetInt32();
else
throw new JsonException();
break;
}
case 1:
{
// expect a type - a string token
if (reader.TokenType == JsonTokenType.String)
type = reader.GetString();
else
throw new JsonException();
break;
}
default:
// too many elements
string? type = reader.GetString();
reader.Read(); // end of array for case 3
if (reader.TokenType != JsonTokenType.EndArray)
throw new JsonException();
return new GlobalDescriptor { Type = type, Value = valueCase2or3 };
}
eltIdx++;
else
throw new JsonException();
}
throw new JsonException();
}

public override void Write(Utf8JsonWriter writer, FieldDescriptor value, JsonSerializerOptions options)
public override void Write(Utf8JsonWriter writer, GlobalDescriptor value, JsonSerializerOptions options)
{
throw new NotImplementedException();
}
}

// Somewhat flexible parsing of numbers, allowing json number tokens or strings as decimal or hex, possibly negatated.
private static bool GetUInt64FromToken(ref Utf8JsonReader reader, out ulong value)
{
if (reader.TokenType == JsonTokenType.Number)
{
if (reader.TryGetUInt64(out value))
return true;
else if (reader.TryGetInt64(out long signedValue))
{
value = (ulong)signedValue;
return true;
}
}
if (reader.TokenType == JsonTokenType.String)
{
var s = reader.GetString();
if (s == null)
{
value = 0u;
return false;
}
if (ulong.TryParse(s, out value))
return true;
if (long.TryParse(s, out long signedValue))
{
value = (ulong)signedValue;
return true;
}
if ((s.StartsWith("0x") || s.StartsWith("0X")) &&
ulong.TryParse(s.AsSpan(2), System.Globalization.NumberStyles.HexNumber, null, out value))
return true;
if ((s.StartsWith("-0x") || s.StartsWith("-0X")) &&
ulong.TryParse(s.AsSpan(3), System.Globalization.NumberStyles.HexNumber, null, out ulong negValue))
{
value = ~negValue + 1; // twos complement
return true;
}
}
value = 0;
return false;
}

// Somewhat flexible parsing of numbers, allowing json number tokens or strings as either decimal or hex, possibly negated
private static bool GetInt32FromToken(ref Utf8JsonReader reader, out int value)
{
if (reader.TokenType == JsonTokenType.Number)
{
value = reader.GetInt32();
return true;
}
if (reader.TokenType == JsonTokenType.String)
{
var s = reader.GetString();
if (s == null)
{
value = 0;
return false;
}
if (int.TryParse(s, out value))
return true;
if ((s.StartsWith("0x") || s.StartsWith("0X")) &&
int.TryParse(s.AsSpan(2), System.Globalization.NumberStyles.HexNumber, null, out value))
return true;
if ((s.StartsWith("-0x") || s.StartsWith("-0X")) &&
int.TryParse(s.AsSpan(3), System.Globalization.NumberStyles.HexNumber, null, out int negValue))
{
value = -negValue;
return true;
}
}
value = 0;
return false;
}

}
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