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-rw-r--r--gfx/skia/skia/src/utils/SkJSON.cpp933
1 files changed, 933 insertions, 0 deletions
diff --git a/gfx/skia/skia/src/utils/SkJSON.cpp b/gfx/skia/skia/src/utils/SkJSON.cpp
new file mode 100644
index 0000000000..1d237f8d67
--- /dev/null
+++ b/gfx/skia/skia/src/utils/SkJSON.cpp
@@ -0,0 +1,933 @@
+/*
+ * Copyright 2018 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "src/utils/SkJSON.h"
+
+#include "include/core/SkData.h"
+#include "include/core/SkRefCnt.h"
+#include "include/core/SkStream.h"
+#include "include/core/SkString.h"
+#include "include/private/base/SkDebug.h"
+#include "include/private/base/SkMalloc.h"
+#include "include/private/base/SkTo.h"
+#include "include/utils/SkParse.h"
+#include "src/base/SkUTF.h"
+
+#include <cmath>
+#include <cstdint>
+#include <cstdlib>
+#include <limits>
+#include <new>
+#include <tuple>
+#include <vector>
+
+namespace skjson {
+
+// #define SK_JSON_REPORT_ERRORS
+
+static_assert( sizeof(Value) == 8, "");
+static_assert(alignof(Value) == 8, "");
+
+static constexpr size_t kRecAlign = alignof(Value);
+
+void Value::init_tagged(Tag t) {
+ memset(fData8, 0, sizeof(fData8));
+ fData8[0] = SkTo<uint8_t>(t);
+ SkASSERT(this->getTag() == t);
+}
+
+// Pointer values store a type (in the lower kTagBits bits) and a pointer.
+void Value::init_tagged_pointer(Tag t, void* p) {
+ if (sizeof(Value) == sizeof(uintptr_t)) {
+ *this->cast<uintptr_t>() = reinterpret_cast<uintptr_t>(p);
+ // For 64-bit, we rely on the pointer lower bits being zero.
+ SkASSERT(!(fData8[0] & kTagMask));
+ fData8[0] |= SkTo<uint8_t>(t);
+ } else {
+ // For 32-bit, we store the pointer in the upper word
+ SkASSERT(sizeof(Value) == sizeof(uintptr_t) * 2);
+ this->init_tagged(t);
+ *this->cast<uintptr_t>() = reinterpret_cast<uintptr_t>(p);
+ }
+
+ SkASSERT(this->getTag() == t);
+ SkASSERT(this->ptr<void>() == p);
+}
+
+NullValue::NullValue() {
+ this->init_tagged(Tag::kNull);
+ SkASSERT(this->getTag() == Tag::kNull);
+}
+
+BoolValue::BoolValue(bool b) {
+ this->init_tagged(Tag::kBool);
+ *this->cast<bool>() = b;
+ SkASSERT(this->getTag() == Tag::kBool);
+}
+
+NumberValue::NumberValue(int32_t i) {
+ this->init_tagged(Tag::kInt);
+ *this->cast<int32_t>() = i;
+ SkASSERT(this->getTag() == Tag::kInt);
+}
+
+NumberValue::NumberValue(float f) {
+ this->init_tagged(Tag::kFloat);
+ *this->cast<float>() = f;
+ SkASSERT(this->getTag() == Tag::kFloat);
+}
+
+// Vector recs point to externally allocated slabs with the following layout:
+//
+// [size_t n] [REC_0] ... [REC_n-1] [optional extra trailing storage]
+//
+// Long strings use extra_alloc_size == 1 to store the \0 terminator.
+//
+template <typename T, size_t extra_alloc_size = 0>
+static void* MakeVector(const void* src, size_t size, SkArenaAlloc& alloc) {
+ // The Ts are already in memory, so their size should be safe.
+ const auto total_size = sizeof(size_t) + size * sizeof(T) + extra_alloc_size;
+ auto* size_ptr = reinterpret_cast<size_t*>(alloc.makeBytesAlignedTo(total_size, kRecAlign));
+
+ *size_ptr = size;
+ sk_careful_memcpy(size_ptr + 1, src, size * sizeof(T));
+
+ return size_ptr;
+}
+
+ArrayValue::ArrayValue(const Value* src, size_t size, SkArenaAlloc& alloc) {
+ this->init_tagged_pointer(Tag::kArray, MakeVector<Value>(src, size, alloc));
+ SkASSERT(this->getTag() == Tag::kArray);
+}
+
+// Strings have two flavors:
+//
+// -- short strings (len <= 7) -> these are stored inline, in the record
+// (one byte reserved for null terminator/type):
+//
+// [str] [\0]|[max_len - actual_len]
+//
+// Storing [max_len - actual_len] allows the 'len' field to double-up as a
+// null terminator when size == max_len (this works 'cause kShortString == 0).
+//
+// -- long strings (len > 7) -> these are externally allocated vectors (VectorRec<char>).
+//
+// The string data plus a null-char terminator are copied over.
+//
+namespace {
+
+// An internal string builder with a fast 8 byte short string load path
+// (for the common case where the string is not at the end of the stream).
+class FastString final : public Value {
+public:
+ FastString(const char* src, size_t size, const char* eos, SkArenaAlloc& alloc) {
+ SkASSERT(src <= eos);
+
+ if (size > kMaxInlineStringSize) {
+ this->initLongString(src, size, alloc);
+ SkASSERT(this->getTag() == Tag::kString);
+ return;
+ }
+
+ // initFastShortString is faster (doh), but requires access to 6 chars past src.
+ if (src && src + 6 <= eos) {
+ this->initFastShortString(src, size);
+ } else {
+ this->initShortString(src, size);
+ }
+
+ SkASSERT(this->getTag() == Tag::kShortString);
+ }
+
+private:
+ // first byte reserved for tagging, \0 terminator => 6 usable chars
+ inline static constexpr size_t kMaxInlineStringSize = sizeof(Value) - 2;
+
+ void initLongString(const char* src, size_t size, SkArenaAlloc& alloc) {
+ SkASSERT(size > kMaxInlineStringSize);
+
+ this->init_tagged_pointer(Tag::kString, MakeVector<char, 1>(src, size, alloc));
+
+ auto* data = this->cast<VectorValue<char, Value::Type::kString>>()->begin();
+ const_cast<char*>(data)[size] = '\0';
+ }
+
+ void initShortString(const char* src, size_t size) {
+ SkASSERT(size <= kMaxInlineStringSize);
+
+ this->init_tagged(Tag::kShortString);
+ sk_careful_memcpy(this->cast<char>(), src, size);
+ // Null terminator provided by init_tagged() above (fData8 is zero-initialized).
+ }
+
+ void initFastShortString(const char* src, size_t size) {
+ SkASSERT(size <= kMaxInlineStringSize);
+
+ uint64_t* s64 = this->cast<uint64_t>();
+
+ // Load 8 chars and mask out the tag and \0 terminator.
+ // Note: we picked kShortString == 0 to avoid setting explicitly below.
+ static_assert(SkToU8(Tag::kShortString) == 0, "please don't break this");
+
+ // Since the first byte is occupied by the tag, we want the string chars [0..5] to land
+ // on bytes [1..6] => the fastest way is to read8 @(src - 1) (always safe, because the
+ // string requires a " prefix at the very least).
+ memcpy(s64, src - 1, 8);
+
+#if defined(SK_CPU_LENDIAN)
+ // The mask for a max-length string (6), with a leading tag and trailing \0 is
+ // 0x00ffffffffffff00. Accounting for the final left-shift, this becomes
+ // 0x0000ffffffffffff.
+ *s64 &= (0x0000ffffffffffffULL >> ((kMaxInlineStringSize - size) * 8)) // trailing \0s
+ << 8; // tag byte
+#else
+ static_assert(false, "Big-endian builds are not supported at this time.");
+#endif
+ }
+};
+
+} // namespace
+
+StringValue::StringValue(const char* src, size_t size, SkArenaAlloc& alloc) {
+ new (this) FastString(src, size, src, alloc);
+}
+
+ObjectValue::ObjectValue(const Member* src, size_t size, SkArenaAlloc& alloc) {
+ this->init_tagged_pointer(Tag::kObject, MakeVector<Member>(src, size, alloc));
+ SkASSERT(this->getTag() == Tag::kObject);
+}
+
+
+// Boring public Value glue.
+
+static int inline_strcmp(const char a[], const char b[]) {
+ for (;;) {
+ char c = *a++;
+ if (c == 0) {
+ break;
+ }
+ if (c != *b++) {
+ return 1;
+ }
+ }
+ return *b != 0;
+}
+
+const Value& ObjectValue::operator[](const char* key) const {
+ // Reverse search for duplicates resolution (policy: return last).
+ const auto* begin = this->begin();
+ const auto* member = this->end();
+
+ while (member > begin) {
+ --member;
+ if (0 == inline_strcmp(key, member->fKey.as<StringValue>().begin())) {
+ return member->fValue;
+ }
+ }
+
+ static const Value g_null = NullValue();
+ return g_null;
+}
+
+namespace {
+
+// Lexer/parser inspired by rapidjson [1], sajson [2] and pjson [3].
+//
+// [1] https://github.com/Tencent/rapidjson/
+// [2] https://github.com/chadaustin/sajson
+// [3] https://pastebin.com/hnhSTL3h
+
+
+// bit 0 (0x01) - plain ASCII string character
+// bit 1 (0x02) - whitespace
+// bit 2 (0x04) - string terminator (" \\ \0 [control chars] **AND } ]** <- see matchString notes)
+// bit 3 (0x08) - 0-9
+// bit 4 (0x10) - 0-9 e E .
+// bit 5 (0x20) - scope terminator (} ])
+static constexpr uint8_t g_token_flags[256] = {
+ // 0 1 2 3 4 5 6 7 8 9 A B C D E F
+ 4, 4, 4, 4, 4, 4, 4, 4, 4, 6, 6, 4, 4, 6, 4, 4, // 0
+ 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, // 1
+ 3, 1, 4, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0x11,1, // 2
+ 0x19,0x19,0x19,0x19,0x19,0x19,0x19,0x19, 0x19,0x19, 1, 1, 1, 1, 1, 1, // 3
+ 1, 1, 1, 1, 1, 0x11,1, 1, 1, 1, 1, 1, 1, 1, 1, 1, // 4
+ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 4,0x25, 1, 1, // 5
+ 1, 1, 1, 1, 1, 0x11,1, 1, 1, 1, 1, 1, 1, 1, 1, 1, // 6
+ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,0x25, 1, 1, // 7
+
+ // 128-255
+ 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
+ 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
+ 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,
+ 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0
+};
+
+static inline bool is_ws(char c) { return g_token_flags[static_cast<uint8_t>(c)] & 0x02; }
+static inline bool is_eostring(char c) { return g_token_flags[static_cast<uint8_t>(c)] & 0x04; }
+static inline bool is_digit(char c) { return g_token_flags[static_cast<uint8_t>(c)] & 0x08; }
+static inline bool is_numeric(char c) { return g_token_flags[static_cast<uint8_t>(c)] & 0x10; }
+static inline bool is_eoscope(char c) { return g_token_flags[static_cast<uint8_t>(c)] & 0x20; }
+
+static inline const char* skip_ws(const char* p) {
+ while (is_ws(*p)) ++p;
+ return p;
+}
+
+static inline float pow10(int32_t exp) {
+ static constexpr float g_pow10_table[63] =
+ {
+ 1.e-031f, 1.e-030f, 1.e-029f, 1.e-028f, 1.e-027f, 1.e-026f, 1.e-025f, 1.e-024f,
+ 1.e-023f, 1.e-022f, 1.e-021f, 1.e-020f, 1.e-019f, 1.e-018f, 1.e-017f, 1.e-016f,
+ 1.e-015f, 1.e-014f, 1.e-013f, 1.e-012f, 1.e-011f, 1.e-010f, 1.e-009f, 1.e-008f,
+ 1.e-007f, 1.e-006f, 1.e-005f, 1.e-004f, 1.e-003f, 1.e-002f, 1.e-001f, 1.e+000f,
+ 1.e+001f, 1.e+002f, 1.e+003f, 1.e+004f, 1.e+005f, 1.e+006f, 1.e+007f, 1.e+008f,
+ 1.e+009f, 1.e+010f, 1.e+011f, 1.e+012f, 1.e+013f, 1.e+014f, 1.e+015f, 1.e+016f,
+ 1.e+017f, 1.e+018f, 1.e+019f, 1.e+020f, 1.e+021f, 1.e+022f, 1.e+023f, 1.e+024f,
+ 1.e+025f, 1.e+026f, 1.e+027f, 1.e+028f, 1.e+029f, 1.e+030f, 1.e+031f
+ };
+
+ static constexpr int32_t k_exp_offset = std::size(g_pow10_table) / 2;
+
+ // We only support negative exponents for now.
+ SkASSERT(exp <= 0);
+
+ return (exp >= -k_exp_offset) ? g_pow10_table[exp + k_exp_offset]
+ : std::pow(10.0f, static_cast<float>(exp));
+}
+
+class DOMParser {
+public:
+ explicit DOMParser(SkArenaAlloc& alloc)
+ : fAlloc(alloc) {
+ fValueStack.reserve(kValueStackReserve);
+ fUnescapeBuffer.reserve(kUnescapeBufferReserve);
+ }
+
+ Value parse(const char* p, size_t size) {
+ if (!size) {
+ return this->error(NullValue(), p, "invalid empty input");
+ }
+
+ const char* p_stop = p + size - 1;
+
+ // We're only checking for end-of-stream on object/array close('}',']'),
+ // so we must trim any whitespace from the buffer tail.
+ while (p_stop > p && is_ws(*p_stop)) --p_stop;
+
+ SkASSERT(p_stop >= p && p_stop < p + size);
+ if (!is_eoscope(*p_stop)) {
+ return this->error(NullValue(), p_stop, "invalid top-level value");
+ }
+
+ p = skip_ws(p);
+
+ switch (*p) {
+ case '{':
+ goto match_object;
+ case '[':
+ goto match_array;
+ default:
+ return this->error(NullValue(), p, "invalid top-level value");
+ }
+
+ match_object:
+ SkASSERT(*p == '{');
+ p = skip_ws(p + 1);
+
+ this->pushObjectScope();
+
+ if (*p == '}') goto pop_object;
+
+ // goto match_object_key;
+ match_object_key:
+ p = skip_ws(p);
+ if (*p != '"') return this->error(NullValue(), p, "expected object key");
+
+ p = this->matchString(p, p_stop, [this](const char* key, size_t size, const char* eos) {
+ this->pushObjectKey(key, size, eos);
+ });
+ if (!p) return NullValue();
+
+ p = skip_ws(p);
+ if (*p != ':') return this->error(NullValue(), p, "expected ':' separator");
+
+ ++p;
+
+ // goto match_value;
+ match_value:
+ p = skip_ws(p);
+
+ switch (*p) {
+ case '\0':
+ return this->error(NullValue(), p, "unexpected input end");
+ case '"':
+ p = this->matchString(p, p_stop, [this](const char* str, size_t size, const char* eos) {
+ this->pushString(str, size, eos);
+ });
+ break;
+ case '[':
+ goto match_array;
+ case 'f':
+ p = this->matchFalse(p);
+ break;
+ case 'n':
+ p = this->matchNull(p);
+ break;
+ case 't':
+ p = this->matchTrue(p);
+ break;
+ case '{':
+ goto match_object;
+ default:
+ p = this->matchNumber(p);
+ break;
+ }
+
+ if (!p) return NullValue();
+
+ // goto match_post_value;
+ match_post_value:
+ SkASSERT(!this->inTopLevelScope());
+
+ p = skip_ws(p);
+ switch (*p) {
+ case ',':
+ ++p;
+ if (this->inObjectScope()) {
+ goto match_object_key;
+ } else {
+ SkASSERT(this->inArrayScope());
+ goto match_value;
+ }
+ case ']':
+ goto pop_array;
+ case '}':
+ goto pop_object;
+ default:
+ return this->error(NullValue(), p - 1, "unexpected value-trailing token");
+ }
+
+ // unreachable
+ SkASSERT(false);
+
+ pop_object:
+ SkASSERT(*p == '}');
+
+ if (this->inArrayScope()) {
+ return this->error(NullValue(), p, "unexpected object terminator");
+ }
+
+ this->popObjectScope();
+
+ // goto pop_common
+ pop_common:
+ SkASSERT(is_eoscope(*p));
+
+ if (this->inTopLevelScope()) {
+ SkASSERT(fValueStack.size() == 1);
+
+ // Success condition: parsed the top level element and reached the stop token.
+ return p == p_stop
+ ? fValueStack.front()
+ : this->error(NullValue(), p + 1, "trailing root garbage");
+ }
+
+ if (p == p_stop) {
+ return this->error(NullValue(), p, "unexpected end-of-input");
+ }
+
+ ++p;
+
+ goto match_post_value;
+
+ match_array:
+ SkASSERT(*p == '[');
+ p = skip_ws(p + 1);
+
+ this->pushArrayScope();
+
+ if (*p != ']') goto match_value;
+
+ // goto pop_array;
+ pop_array:
+ SkASSERT(*p == ']');
+
+ if (this->inObjectScope()) {
+ return this->error(NullValue(), p, "unexpected array terminator");
+ }
+
+ this->popArrayScope();
+
+ goto pop_common;
+
+ SkASSERT(false);
+ return NullValue();
+ }
+
+ std::tuple<const char*, const SkString> getError() const {
+ return std::make_tuple(fErrorToken, fErrorMessage);
+ }
+
+private:
+ SkArenaAlloc& fAlloc;
+
+ // Pending values stack.
+ inline static constexpr size_t kValueStackReserve = 256;
+ std::vector<Value> fValueStack;
+
+ // String unescape buffer.
+ inline static constexpr size_t kUnescapeBufferReserve = 512;
+ std::vector<char> fUnescapeBuffer;
+
+ // Tracks the current object/array scope, as an index into fStack:
+ //
+ // - for objects: fScopeIndex = (index of first value in scope)
+ // - for arrays : fScopeIndex = -(index of first value in scope)
+ //
+ // fScopeIndex == 0 IFF we are at the top level (no current/active scope).
+ intptr_t fScopeIndex = 0;
+
+ // Error reporting.
+ const char* fErrorToken = nullptr;
+ SkString fErrorMessage;
+
+ bool inTopLevelScope() const { return fScopeIndex == 0; }
+ bool inObjectScope() const { return fScopeIndex > 0; }
+ bool inArrayScope() const { return fScopeIndex < 0; }
+
+ // Helper for masquerading raw primitive types as Values (bypassing tagging, etc).
+ template <typename T>
+ class RawValue final : public Value {
+ public:
+ explicit RawValue(T v) {
+ static_assert(sizeof(T) <= sizeof(Value), "");
+ *this->cast<T>() = v;
+ }
+
+ T operator *() const { return *this->cast<T>(); }
+ };
+
+ template <typename VectorT>
+ void popScopeAsVec(size_t scope_start) {
+ SkASSERT(scope_start > 0);
+ SkASSERT(scope_start <= fValueStack.size());
+
+ using T = typename VectorT::ValueT;
+ static_assert( sizeof(T) >= sizeof(Value), "");
+ static_assert( sizeof(T) % sizeof(Value) == 0, "");
+ static_assert(alignof(T) == alignof(Value), "");
+
+ const auto scope_count = fValueStack.size() - scope_start,
+ count = scope_count / (sizeof(T) / sizeof(Value));
+ SkASSERT(scope_count % (sizeof(T) / sizeof(Value)) == 0);
+
+ const auto* begin = reinterpret_cast<const T*>(fValueStack.data() + scope_start);
+
+ // Restore the previous scope index from saved placeholder value,
+ // and instantiate as a vector of values in scope.
+ auto& placeholder = fValueStack[scope_start - 1];
+ fScopeIndex = *static_cast<RawValue<intptr_t>&>(placeholder);
+ placeholder = VectorT(begin, count, fAlloc);
+
+ // Drop the (consumed) values in scope.
+ fValueStack.resize(scope_start);
+ }
+
+ void pushObjectScope() {
+ // Save a scope index now, and then later we'll overwrite this value as the Object itself.
+ fValueStack.push_back(RawValue<intptr_t>(fScopeIndex));
+
+ // New object scope.
+ fScopeIndex = SkTo<intptr_t>(fValueStack.size());
+ }
+
+ void popObjectScope() {
+ SkASSERT(this->inObjectScope());
+ this->popScopeAsVec<ObjectValue>(SkTo<size_t>(fScopeIndex));
+
+ SkDEBUGCODE(
+ const auto& obj = fValueStack.back().as<ObjectValue>();
+ SkASSERT(obj.is<ObjectValue>());
+ for (const auto& member : obj) {
+ SkASSERT(member.fKey.is<StringValue>());
+ }
+ )
+ }
+
+ void pushArrayScope() {
+ // Save a scope index now, and then later we'll overwrite this value as the Array itself.
+ fValueStack.push_back(RawValue<intptr_t>(fScopeIndex));
+
+ // New array scope.
+ fScopeIndex = -SkTo<intptr_t>(fValueStack.size());
+ }
+
+ void popArrayScope() {
+ SkASSERT(this->inArrayScope());
+ this->popScopeAsVec<ArrayValue>(SkTo<size_t>(-fScopeIndex));
+
+ SkDEBUGCODE(
+ const auto& arr = fValueStack.back().as<ArrayValue>();
+ SkASSERT(arr.is<ArrayValue>());
+ )
+ }
+
+ void pushObjectKey(const char* key, size_t size, const char* eos) {
+ SkASSERT(this->inObjectScope());
+ SkASSERT(fValueStack.size() >= SkTo<size_t>(fScopeIndex));
+ SkASSERT(!((fValueStack.size() - SkTo<size_t>(fScopeIndex)) & 1));
+ this->pushString(key, size, eos);
+ }
+
+ void pushTrue() {
+ fValueStack.push_back(BoolValue(true));
+ }
+
+ void pushFalse() {
+ fValueStack.push_back(BoolValue(false));
+ }
+
+ void pushNull() {
+ fValueStack.push_back(NullValue());
+ }
+
+ void pushString(const char* s, size_t size, const char* eos) {
+ fValueStack.push_back(FastString(s, size, eos, fAlloc));
+ }
+
+ void pushInt32(int32_t i) {
+ fValueStack.push_back(NumberValue(i));
+ }
+
+ void pushFloat(float f) {
+ fValueStack.push_back(NumberValue(f));
+ }
+
+ template <typename T>
+ T error(T&& ret_val, const char* p, const char* msg) {
+#if defined(SK_JSON_REPORT_ERRORS)
+ fErrorToken = p;
+ fErrorMessage.set(msg);
+#endif
+ return ret_val;
+ }
+
+ const char* matchTrue(const char* p) {
+ SkASSERT(p[0] == 't');
+
+ if (p[1] == 'r' && p[2] == 'u' && p[3] == 'e') {
+ this->pushTrue();
+ return p + 4;
+ }
+
+ return this->error(nullptr, p, "invalid token");
+ }
+
+ const char* matchFalse(const char* p) {
+ SkASSERT(p[0] == 'f');
+
+ if (p[1] == 'a' && p[2] == 'l' && p[3] == 's' && p[4] == 'e') {
+ this->pushFalse();
+ return p + 5;
+ }
+
+ return this->error(nullptr, p, "invalid token");
+ }
+
+ const char* matchNull(const char* p) {
+ SkASSERT(p[0] == 'n');
+
+ if (p[1] == 'u' && p[2] == 'l' && p[3] == 'l') {
+ this->pushNull();
+ return p + 4;
+ }
+
+ return this->error(nullptr, p, "invalid token");
+ }
+
+ const std::vector<char>* unescapeString(const char* begin, const char* end) {
+ fUnescapeBuffer.clear();
+
+ for (const auto* p = begin; p != end; ++p) {
+ if (*p != '\\') {
+ fUnescapeBuffer.push_back(*p);
+ continue;
+ }
+
+ if (++p == end) {
+ return nullptr;
+ }
+
+ switch (*p) {
+ case '"': fUnescapeBuffer.push_back( '"'); break;
+ case '\\': fUnescapeBuffer.push_back('\\'); break;
+ case '/': fUnescapeBuffer.push_back( '/'); break;
+ case 'b': fUnescapeBuffer.push_back('\b'); break;
+ case 'f': fUnescapeBuffer.push_back('\f'); break;
+ case 'n': fUnescapeBuffer.push_back('\n'); break;
+ case 'r': fUnescapeBuffer.push_back('\r'); break;
+ case 't': fUnescapeBuffer.push_back('\t'); break;
+ case 'u': {
+ if (p + 4 >= end) {
+ return nullptr;
+ }
+
+ uint32_t hexed;
+ const char hex_str[] = {p[1], p[2], p[3], p[4], '\0'};
+ const auto* eos = SkParse::FindHex(hex_str, &hexed);
+ if (!eos || *eos) {
+ return nullptr;
+ }
+
+ char utf8[SkUTF::kMaxBytesInUTF8Sequence];
+ const auto utf8_len = SkUTF::ToUTF8(SkTo<SkUnichar>(hexed), utf8);
+ fUnescapeBuffer.insert(fUnescapeBuffer.end(), utf8, utf8 + utf8_len);
+ p += 4;
+ } break;
+ default: return nullptr;
+ }
+ }
+
+ return &fUnescapeBuffer;
+ }
+
+ template <typename MatchFunc>
+ const char* matchString(const char* p, const char* p_stop, MatchFunc&& func) {
+ SkASSERT(*p == '"');
+ const auto* s_begin = p + 1;
+ bool requires_unescape = false;
+
+ do {
+ // Consume string chars.
+ // This is the fast path, and hopefully we only hit it once then quick-exit below.
+ for (p = p + 1; !is_eostring(*p); ++p);
+
+ if (*p == '"') {
+ // Valid string found.
+ if (!requires_unescape) {
+ func(s_begin, p - s_begin, p_stop);
+ } else {
+ // Slow unescape. We could avoid this extra copy with some effort,
+ // but in practice escaped strings should be rare.
+ const auto* buf = this->unescapeString(s_begin, p);
+ if (!buf) {
+ break;
+ }
+
+ SkASSERT(!buf->empty());
+ func(buf->data(), buf->size(), buf->data() + buf->size() - 1);
+ }
+ return p + 1;
+ }
+
+ if (*p == '\\') {
+ requires_unescape = true;
+ ++p;
+ continue;
+ }
+
+ // End-of-scope chars are special: we use them to tag the end of the input.
+ // Thus they cannot be consumed indiscriminately -- we need to check if we hit the
+ // end of the input. To that effect, we treat them as string terminators above,
+ // then we catch them here.
+ if (is_eoscope(*p)) {
+ continue;
+ }
+
+ // Invalid/unexpected char.
+ break;
+ } while (p != p_stop);
+
+ // Premature end-of-input, or illegal string char.
+ return this->error(nullptr, s_begin - 1, "invalid string");
+ }
+
+ const char* matchFastFloatDecimalPart(const char* p, int sign, float f, int exp) {
+ SkASSERT(exp <= 0);
+
+ for (;;) {
+ if (!is_digit(*p)) break;
+ f = f * 10.f + (*p++ - '0'); --exp;
+ if (!is_digit(*p)) break;
+ f = f * 10.f + (*p++ - '0'); --exp;
+ }
+
+ const auto decimal_scale = pow10(exp);
+ if (is_numeric(*p) || !decimal_scale) {
+ SkASSERT((*p == '.' || *p == 'e' || *p == 'E') || !decimal_scale);
+ // Malformed input, or an (unsupported) exponent, or a collapsed decimal factor.
+ return nullptr;
+ }
+
+ this->pushFloat(sign * f * decimal_scale);
+
+ return p;
+ }
+
+ const char* matchFastFloatPart(const char* p, int sign, float f) {
+ for (;;) {
+ if (!is_digit(*p)) break;
+ f = f * 10.f + (*p++ - '0');
+ if (!is_digit(*p)) break;
+ f = f * 10.f + (*p++ - '0');
+ }
+
+ if (!is_numeric(*p)) {
+ // Matched (integral) float.
+ this->pushFloat(sign * f);
+ return p;
+ }
+
+ return (*p == '.') ? this->matchFastFloatDecimalPart(p + 1, sign, f, 0)
+ : nullptr;
+ }
+
+ const char* matchFast32OrFloat(const char* p) {
+ int sign = 1;
+ if (*p == '-') {
+ sign = -1;
+ ++p;
+ }
+
+ const auto* digits_start = p;
+
+ int32_t n32 = 0;
+
+ // This is the largest absolute int32 value we can handle before
+ // risking overflow *on the next digit* (214748363).
+ static constexpr int32_t kMaxInt32 = (std::numeric_limits<int32_t>::max() - 9) / 10;
+
+ if (is_digit(*p)) {
+ n32 = (*p++ - '0');
+ for (;;) {
+ if (!is_digit(*p) || n32 > kMaxInt32) break;
+ n32 = n32 * 10 + (*p++ - '0');
+ }
+ }
+
+ if (!is_numeric(*p)) {
+ // Did we actually match any digits?
+ if (p > digits_start) {
+ this->pushInt32(sign * n32);
+ return p;
+ }
+ return nullptr;
+ }
+
+ if (*p == '.') {
+ const auto* decimals_start = ++p;
+
+ int exp = 0;
+
+ for (;;) {
+ if (!is_digit(*p) || n32 > kMaxInt32) break;
+ n32 = n32 * 10 + (*p++ - '0'); --exp;
+ if (!is_digit(*p) || n32 > kMaxInt32) break;
+ n32 = n32 * 10 + (*p++ - '0'); --exp;
+ }
+
+ if (!is_numeric(*p)) {
+ // Did we actually match any digits?
+ if (p > decimals_start) {
+ this->pushFloat(sign * n32 * pow10(exp));
+ return p;
+ }
+ return nullptr;
+ }
+
+ if (n32 > kMaxInt32) {
+ // we ran out on n32 bits
+ return this->matchFastFloatDecimalPart(p, sign, n32, exp);
+ }
+ }
+
+ return this->matchFastFloatPart(p, sign, n32);
+ }
+
+ const char* matchNumber(const char* p) {
+ if (const auto* fast = this->matchFast32OrFloat(p)) return fast;
+
+ // slow fallback
+ char* matched;
+ float f = strtof(p, &matched);
+ if (matched > p) {
+ this->pushFloat(f);
+ return matched;
+ }
+ return this->error(nullptr, p, "invalid numeric token");
+ }
+};
+
+void Write(const Value& v, SkWStream* stream) {
+ switch (v.getType()) {
+ case Value::Type::kNull:
+ stream->writeText("null");
+ break;
+ case Value::Type::kBool:
+ stream->writeText(*v.as<BoolValue>() ? "true" : "false");
+ break;
+ case Value::Type::kNumber:
+ stream->writeScalarAsText(*v.as<NumberValue>());
+ break;
+ case Value::Type::kString:
+ stream->writeText("\"");
+ stream->writeText(v.as<StringValue>().begin());
+ stream->writeText("\"");
+ break;
+ case Value::Type::kArray: {
+ const auto& array = v.as<ArrayValue>();
+ stream->writeText("[");
+ bool first_value = true;
+ for (const auto& entry : array) {
+ if (!first_value) stream->writeText(",");
+ Write(entry, stream);
+ first_value = false;
+ }
+ stream->writeText("]");
+ break;
+ }
+ case Value::Type::kObject:
+ const auto& object = v.as<ObjectValue>();
+ stream->writeText("{");
+ bool first_member = true;
+ for (const auto& member : object) {
+ SkASSERT(member.fKey.getType() == Value::Type::kString);
+ if (!first_member) stream->writeText(",");
+ Write(member.fKey, stream);
+ stream->writeText(":");
+ Write(member.fValue, stream);
+ first_member = false;
+ }
+ stream->writeText("}");
+ break;
+ }
+}
+
+} // namespace
+
+SkString Value::toString() const {
+ SkDynamicMemoryWStream wstream;
+ Write(*this, &wstream);
+ const auto data = wstream.detachAsData();
+ // TODO: is there a better way to pass data around without copying?
+ return SkString(static_cast<const char*>(data->data()), data->size());
+}
+
+static constexpr size_t kMinChunkSize = 4096;
+
+DOM::DOM(const char* data, size_t size)
+ : fAlloc(kMinChunkSize) {
+ DOMParser parser(fAlloc);
+
+ fRoot = parser.parse(data, size);
+}
+
+void DOM::write(SkWStream* stream) const {
+ Write(fRoot, stream);
+}
+
+} // namespace skjson
generated by cgit v1.2.3 (git 2.39.1) at 2025-01-09 03:54:23 +0000