json::OStream allows writing well-formed JSON without materializing all structures as json::Value ahead of time. More...
#include "llvm/Support/JSON.h"
Public Types | |
| using | Block = llvm::function_ref<void()> |
Public Member Functions | |
| OStream (llvm::raw_ostream &OS, unsigned IndentSize=0) | |
| ~OStream () | |
| void | flush () |
| Flushes the underlying ostream. OStream does not buffer internally. | |
| LLVM_ABI void | value (const Value &V) |
| Emit a self-contained value (number, string, vector<string> etc). | |
| void | array (Block Contents) |
| Emit an array whose elements are emitted in the provided Block. | |
| void | object (Block Contents) |
| Emit an object whose elements are emitted in the provided Block. | |
| void | rawValue (llvm::function_ref< void(raw_ostream &)> Contents) |
| Emit an externally-serialized value. | |
| void | rawValue (llvm::StringRef Contents) |
| LLVM_ABI void | comment (llvm::StringRef) |
| Emit a JavaScript comment associated with the next printed value. | |
| void | attribute (llvm::StringRef Key, const Value &Contents) |
| Emit an attribute whose value is self-contained (number, vector<int> etc). | |
| void | attributeArray (llvm::StringRef Key, Block Contents) |
| Emit an attribute whose value is an array with elements from the Block. | |
| void | attributeObject (llvm::StringRef Key, Block Contents) |
| Emit an attribute whose value is an object with attributes from the Block. | |
| LLVM_ABI void | arrayBegin () |
| LLVM_ABI void | arrayEnd () |
| LLVM_ABI void | objectBegin () |
| LLVM_ABI void | objectEnd () |
| LLVM_ABI void | attributeBegin (llvm::StringRef Key) |
| LLVM_ABI void | attributeEnd () |
| LLVM_ABI raw_ostream & | rawValueBegin () |
| LLVM_ABI void | rawValueEnd () |
Detailed Description
json::OStream allows writing well-formed JSON without materializing all structures as json::Value ahead of time.
It's faster, lower-level, and less safe than OS << json::Value. It also allows emitting more constructs, such as comments.
Only one "top-level" object can be written to a stream. Simplest usage involves passing lambdas (Blocks) to fill in containers:
json::OStream J(OS); J.array([&]{ for (const Event &E : Events) J.object([&] { J.attribute("timestamp", int64_t(E.Time)); J.attributeArray("participants", [&] { for (const Participant &P : E.Participants) J.value(P.toString()); }); }); });
This would produce JSON like:
[ { "timestamp": 19287398741, "participants": [ "King Kong", "Miley Cyrus", "Cleopatra" ] }, ... ]
The lower level begin/end methods (arrayBegin()) are more flexible but care must be taken to pair them correctly:
json::OStream J(OS); for (const Event &E : Events) { J.objectBegin(); J.attribute("timestamp", int64_t(E.Time)); J.attributeBegin("participants"); for (const Participant &P : E.Participants) J.value(P.toString()); J.attributeEnd(); J.objectEnd(); } J.arrayEnd();
If the call sequence isn't valid JSON, asserts will fire in debug mode. This can be mismatched begin()/end() pairs, trying to emit attributes inside an array, and so on. With asserts disabled, this is undefined behavior.
Member Typedef Documentation
◆ Block
| using llvm::json::OStream::Block = llvm::function_ref<void()> |
Constructor & Destructor Documentation
◆ OStream()
|
inlineexplicit |
◆ ~OStream()
|
inline |
Member Function Documentation
◆ array()
|
inline |
Emit an array whose elements are emitted in the provided Block.
Definition at line 1022 of file JSON.h.
References arrayBegin(), and arrayEnd().
Referenced by llvm::json::abbreviateChildren(), attributeArray(), llvm::json::Path::Root::printErrorContext(), and value().
◆ arrayBegin()
| void llvm::json::OStream::arrayBegin | ( | ) |
Definition at line 833 of file JSON.cpp.
Referenced by array(), llvm::sampleprof::SampleProfileReader::dumpJson(), and llvm::TimeTraceProfiler::write().
◆ arrayEnd()
| void llvm::json::OStream::arrayEnd | ( | ) |
Definition at line 841 of file JSON.cpp.
References assert().
Referenced by array(), llvm::sampleprof::SampleProfileReader::dumpJson(), and llvm::TimeTraceProfiler::write().
◆ attribute()
|
inline |
Emit an attribute whose value is self-contained (number, vector<int> etc).
Definition at line 1053 of file JSON.h.
References llvm::InnerAnalysisManagerProxy< AnalysisManagerT, IRUnitT, ExtraArgTs... >::Key, and value().
Referenced by dumpFunctionProfileJson(), llvm::Logger::startObservation(), llvm::Logger::switchContext(), llvm::TensorSpec::toJSON(), value(), llvm::TimeTraceProfiler::write(), and llvm::offloading::writePropertiesToJSON().
◆ attributeArray()
|
inline |
Emit an attribute whose value is an array with elements from the Block.
Definition at line 1057 of file JSON.h.
References array(), and llvm::InnerAnalysisManagerProxy< AnalysisManagerT, IRUnitT, ExtraArgTs... >::Key.
Referenced by dumpFunctionProfileJson(), and llvm::TensorSpec::toJSON().
◆ attributeBegin()
| void llvm::json::OStream::attributeBegin | ( | llvm::StringRef | Key | ) |
Definition at line 871 of file JSON.cpp.
References assert(), llvm::json::fixUTF8(), llvm::InnerAnalysisManagerProxy< AnalysisManagerT, IRUnitT, ExtraArgTs... >::Key, llvm::json::isUTF8(), LLVM_LIKELY, and llvm::json::quote().
Referenced by llvm::json::abbreviateChildren(), llvm::json::Path::Root::printErrorContext(), and llvm::TimeTraceProfiler::write().
◆ attributeEnd()
| void llvm::json::OStream::attributeEnd | ( | ) |
Definition at line 891 of file JSON.cpp.
References assert().
Referenced by llvm::json::abbreviateChildren(), llvm::json::Path::Root::printErrorContext(), and llvm::TimeTraceProfiler::write().
◆ attributeObject()
|
inline |
Emit an attribute whose value is an object with attributes from the Block.
Definition at line 1061 of file JSON.h.
References llvm::InnerAnalysisManagerProxy< AnalysisManagerT, IRUnitT, ExtraArgTs... >::Key, and object().
Referenced by llvm::TimeTraceProfiler::write(), and llvm::offloading::writePropertiesToJSON().
◆ comment()
| void llvm::json::OStream::comment | ( | llvm::StringRef | Comment | ) |
Emit a JavaScript comment associated with the next printed value.
The string must be valid until the next attribute or value is emitted. Comments are not part of standard JSON, and many parsers reject them!
Definition at line 796 of file JSON.cpp.
References assert().
Referenced by llvm::json::Path::Root::printErrorContext().
◆ flush()
|
inline |
◆ object()
|
inline |
Emit an object whose elements are emitted in the provided Block.
Definition at line 1028 of file JSON.h.
References objectBegin(), and objectEnd().
Referenced by llvm::json::abbreviateChildren(), attributeObject(), dumpFunctionProfileJson(), llvm::json::Path::Root::printErrorContext(), llvm::Logger::startObservation(), llvm::Logger::switchContext(), llvm::TensorSpec::toJSON(), value(), llvm::TimeTraceProfiler::write(), and llvm::offloading::writePropertiesToJSON().
◆ objectBegin()
| void llvm::json::OStream::objectBegin | ( | ) |
Definition at line 852 of file JSON.cpp.
Referenced by object(), and llvm::TimeTraceProfiler::write().
◆ objectEnd()
| void llvm::json::OStream::objectEnd | ( | ) |
Definition at line 860 of file JSON.cpp.
References assert().
Referenced by object(), and llvm::TimeTraceProfiler::write().
◆ rawValue() [1/2]
|
inline |
Emit an externally-serialized value.
The caller must write exactly one valid JSON value to the provided stream. No validation or formatting of this value occurs.
Definition at line 1036 of file JSON.h.
References rawValueBegin(), and rawValueEnd().
Referenced by llvm::json::abbreviate(), and rawValue().
◆ rawValue() [2/2]
|
inline |
Definition at line 1041 of file JSON.h.
References rawValue().
◆ rawValueBegin()
| raw_ostream & llvm::json::OStream::rawValueBegin | ( | ) |
Definition at line 899 of file JSON.cpp.
Referenced by rawValue().
◆ rawValueEnd()
| void llvm::json::OStream::rawValueEnd | ( | ) |
◆ value()
Emit a self-contained value (number, string, vector<string> etc).
Definition at line 747 of file JSON.cpp.
References llvm::json::Value::Array, array(), attribute(), llvm::json::Value::Boolean, E(), llvm::format(), llvm::json::Value::Null, llvm::json::Value::Number, llvm::json::Value::Object, object(), llvm::json::quote(), llvm::json::sortedElements(), llvm::json::Value::String, and value().
Referenced by llvm::json::abbreviate(), llvm::json::abbreviateChildren(), attribute(), llvm::format_provider< llvm::json::Value >::format(), llvm::json::operator<<(), llvm::TensorSpec::toJSON(), llvm::mustache::toMustacheString(), and value().
The documentation for this class was generated from the following files:
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