Mirrors
/
protobuf
mirror of https://github.com/protocolbuffers/protobuf.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

Optimize startup be reducing selector lookup. 

Move away from looking up selectors at proto initialization time to doing optimized string compares at implementation resolving time.

PiperOrigin-RevId: 623183331
pull/16444/head
Dave MacLachlan 2024-04-09 09:00:58 -07:00 committed by Copybara-Service
parent e22539bdd8
commit b375d010bf
4 changed files with 269 additions and 125 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

55
objectivec/GPBDescriptor.m
View File

@ -51,40 +51,6 @@ static const char kParentClassValueKey = 0;
static const char kClassNameSuffixKey = 0;
static const char kFileDescriptorCacheKey = 0;
// Utility function to generate selectors on the fly.
static SEL SelFromStrings(const char *prefix, const char *middle, const char *suffix,
BOOL takesArg) {
if (prefix == NULL && suffix == NULL && !takesArg) {
return sel_getUid(middle);
}
const size_t prefixLen = prefix != NULL ? strlen(prefix) : 0;
const size_t middleLen = strlen(middle);
const size_t suffixLen = suffix != NULL ? strlen(suffix) : 0;
size_t totalLen = prefixLen + middleLen + suffixLen + 1; // include space for null on end.
if (takesArg) {
totalLen += 1;
}
char buffer[totalLen];
if (prefix != NULL) {
memcpy(buffer, prefix, prefixLen);
memcpy(buffer + prefixLen, middle, middleLen);
buffer[prefixLen] = (char)toupper(buffer[prefixLen]);
} else {
memcpy(buffer, middle, middleLen);
}
if (suffix != NULL) {
memcpy(buffer + prefixLen + middleLen, suffix, suffixLen);
}
if (takesArg) {
buffer[totalLen - 2] = ':';
}
// Always null terminate it.
buffer[totalLen - 1] = 0;
SEL result = sel_getUid(buffer);
return result;
}
static NSArray *NewFieldsArrayForHasIndex(int hasIndex, NSArray *allMessageFields)
__attribute__((ns_returns_retained));
@ -594,8 +560,6 @@ static NSArray *NewFieldsArrayForHasIndex(int hasIndex, NSArray *allMessageField
for (GPBFieldDescriptor *fieldDesc in fields) {
fieldDesc->containingOneof_ = self;
}
caseSel_ = SelFromStrings(NULL, name, "OneOfCase", NO);
}
return self;
}
@ -682,27 +646,9 @@ uint32_t GPBFieldAlternateTag(GPBFieldDescriptor *self) {
coreDesc = description;
}
description_ = coreDesc;
getSel_ = sel_getUid(coreDesc->name);
setSel_ = SelFromStrings("set", coreDesc->name, NULL, YES);
GPBDataType dataType = coreDesc->dataType;
BOOL isMessage = GPBDataTypeIsMessage(dataType);
BOOL isMapOrArray = GPBFieldIsMapOrArray(self);
if (isMapOrArray) {
// map<>/repeated fields get a *Count property (inplace of a has*) to
// support checking if there are any entries without triggering
// autocreation.
hasOrCountSel_ = SelFromStrings(NULL, coreDesc->name, "_Count", NO);
} else {
// It is a single field; it gets has/setHas selectors if...
// - not in a oneof (negative has index)
// - not clearing on zero
if ((coreDesc->hasIndex >= 0) && ((coreDesc->flags & GPBFieldClearHasIvarOnZero) == 0)) {
hasOrCountSel_ = SelFromStrings("has", coreDesc->name, NULL, NO);
setHasSel_ = SelFromStrings("setHas", coreDesc->name, NULL, YES);
}
}
// Extra type specific data.
if (isMessage) {
@ -719,6 +665,7 @@ uint32_t GPBFieldAlternateTag(GPBFieldDescriptor *self) {
}
// Non map<>/repeated fields can have defaults in proto2 syntax.
BOOL isMapOrArray = GPBFieldIsMapOrArray(self);
if (!isMapOrArray && includesDefault) {
defaultValue_ = ((GPBMessageFieldDescriptionWithDefault *)description)->defaultValue;
if (dataType == GPBDataTypeBytes) {

10
objectivec/GPBDescriptor_PackagePrivate.h
View File

@ -80,6 +80,10 @@ typedef struct GPBFileDescription {
// Describes a single field in a protobuf as it is represented as an ivar.
typedef struct GPBMessageFieldDescription {
// Name of ivar.
// Note that we looked into using a SEL here instead (which really is just a C string)
// but there is not a way to initialize an SEL with a constant (@selector is not constant) so the
// additional code generated to initialize the value is actually bigger in size than just using a
// C identifier for large apps.
const char *name;
union {
// className is deprecated and will be removed in favor of clazz.
@ -235,7 +239,6 @@ typedef NS_OPTIONS(uint32_t, GPBDescriptorInitializationFlags) {
@package
const char *name_;
NSArray *fields_;
SEL caseSel_;
}
// name must be long lived.
- (instancetype)initWithName:(const char *)name fields:(NSArray *)fields;
@ -245,11 +248,6 @@ typedef NS_OPTIONS(uint32_t, GPBDescriptorInitializationFlags) {
@package
GPBMessageFieldDescription *description_;
GPB_UNSAFE_UNRETAINED GPBOneofDescriptor *containingOneof_;
SEL getSel_;
SEL setSel_;
SEL hasOrCountSel_; // *Count for map<>/repeated fields, has* otherwise.
SEL setHasSel_;
}
@end

320
objectivec/GPBMessage.m
View File

@ -3216,92 +3216,290 @@ static void ResolveIvarSet(__unsafe_unretained GPBFieldDescriptor *field,
}
}
// Highly optimized routines for determining selector types.
// Meant to only be used by GPBMessage when resolving selectors in
// `+ (BOOL)resolveInstanceMethod:(SEL)sel`.
// These routines are intended to make negative decisions as fast as possible.
GPB_INLINE char GPBFastToUpper(char c) { return (c >= 'a' && c <= 'z') ? (c - 'a' + 'A') : c; }
GPB_INLINE BOOL GPBIsGetSelForField(const char *selName, GPBFieldDescriptor *descriptor) {
// Does 'selName' == '<name>'?
// selName and <name> have to be at least two characters long (i.e. ('a', '\0')" is the shortest
// selector you can have).
return (selName[0] == descriptor->description_->name[0]) &&
(selName[1] == descriptor->description_->name[1]) &&
(strcmp(selName + 1, descriptor->description_->name + 1) == 0);
}
GPB_INLINE BOOL GPBIsSetSelForField(const char *selName, size_t selNameLength,
GPBFieldDescriptor *descriptor) {
// Does 'selName' == 'set<Name>:'?
// Do fastest compares up front
const size_t kSetLength = strlen("set");
// kSetLength is 3 and one for the colon.
if (selNameLength <= kSetLength + 1) {
return NO;
}
if (selName[kSetLength] != GPBFastToUpper(descriptor->description_->name[0])) {
return NO;
}
// NB we check for "set" and the colon later in this routine because we have already checked for
// starting with "s" and ending with ":" in `+resolveInstanceMethod:` before we get here.
if (selName[0] != 's' || selName[1] != 'e' || selName[2] != 't') {
return NO;
}
if (selName[selNameLength - 1] != ':') {
return NO;
}
// Slow path.
size_t nameLength = strlen(descriptor->description_->name);
size_t setSelLength = nameLength + kSetLength + 1;
if (selNameLength != setSelLength) {
return NO;
}
if (strncmp(&selName[kSetLength + 1], descriptor->description_->name + 1, nameLength - 1) != 0) {
return NO;
}
return YES;
}
GPB_INLINE BOOL GPBFieldHasHas(GPBFieldDescriptor *descriptor) {
// It gets has/setHas selectors if...
// - not in a oneof (negative has index)
// - not clearing on zero
return (descriptor->description_->hasIndex >= 0) &&
((descriptor->description_->flags & GPBFieldClearHasIvarOnZero) == 0);
}
GPB_INLINE BOOL GPBIsHasSelForField(const char *selName, size_t selNameLength,
GPBFieldDescriptor *descriptor) {
// Does 'selName' == 'has<Name>'?
// Do fastest compares up front.
const size_t kHasLength = strlen("has");
if (selNameLength <= kHasLength) {
return NO;
}
if (selName[0] != 'h' || selName[1] != 'a' || selName[2] != 's') {
return NO;
}
if (selName[kHasLength] != GPBFastToUpper(descriptor->description_->name[0])) {
return NO;
}
if (!GPBFieldHasHas(descriptor)) {
return NO;
}
// Slow path.
size_t nameLength = strlen(descriptor->description_->name);
size_t setSelLength = nameLength + kHasLength;
if (selNameLength != setSelLength) {
return NO;
}
if (strncmp(&selName[kHasLength + 1], descriptor->description_->name + 1, nameLength - 1) != 0) {
return NO;
}
return YES;
}
GPB_INLINE BOOL GPBIsCountSelForField(const char *selName, size_t selNameLength,
GPBFieldDescriptor *descriptor) {
// Does 'selName' == '<name>_Count'?
// Do fastest compares up front.
if (selName[0] != descriptor->description_->name[0]) {
return NO;
}
const size_t kCountLength = strlen("_Count");
if (selNameLength <= kCountLength) {
return NO;
}
if (selName[selNameLength - kCountLength] != '_') {
return NO;
}
// Slow path.
size_t nameLength = strlen(descriptor->description_->name);
size_t setSelLength = nameLength + kCountLength;
if (selNameLength != setSelLength) {
return NO;
}
if (strncmp(selName, descriptor->description_->name, nameLength) != 0) {
return NO;
}
if (strncmp(&selName[nameLength], "_Count", kCountLength) != 0) {
return NO;
}
return YES;
}
GPB_INLINE BOOL GPBIsSetHasSelForField(const char *selName, size_t selNameLength,
GPBFieldDescriptor *descriptor) {
// Does 'selName' == 'setHas<Name>:'?
// Do fastest compares up front.
const size_t kSetHasLength = strlen("setHas");
// kSetHasLength is 6 and one for the colon.
if (selNameLength <= kSetHasLength + 1) {
return NO;
}
if (selName[selNameLength - 1] != ':') {
return NO;
}
if (selName[kSetHasLength] != GPBFastToUpper(descriptor->description_->name[0])) {
return NO;
}
if (selName[0] != 's' || selName[1] != 'e' || selName[2] != 't' || selName[3] != 'H' ||
selName[4] != 'a' || selName[5] != 's') {
return NO;
}
if (!GPBFieldHasHas(descriptor)) {
return NO;
}
// Slow path.
size_t nameLength = strlen(descriptor->description_->name);
size_t setHasSelLength = nameLength + kSetHasLength + 1;
if (selNameLength != setHasSelLength) {
return NO;
}
if (strncmp(&selName[kSetHasLength + 1], descriptor->description_->name + 1, nameLength - 1) !=
0) {
return NO;
}
return YES;
}
GPB_INLINE BOOL GPBIsCaseOfSelForOneOf(const char *selName, size_t selNameLength,
GPBOneofDescriptor *descriptor) {
// Does 'selName' == '<name>OneOfCase'?
// Do fastest compares up front.
if (selName[0] != descriptor->name_[0]) {
return NO;
}
const size_t kOneOfCaseLength = strlen("OneOfCase");
if (selNameLength <= kOneOfCaseLength) {
return NO;
}
if (selName[selNameLength - kOneOfCaseLength] != 'O') {
return NO;
}
// Slow path.
size_t nameLength = strlen(descriptor->name_);
size_t setSelLength = nameLength + kOneOfCaseLength;
if (selNameLength != setSelLength) {
return NO;
}
if (strncmp(&selName[nameLength], "OneOfCase", kOneOfCaseLength) != 0) {
return NO;
}
if (strncmp(selName, descriptor->name_, nameLength) != 0) {
return NO;
}
return YES;
}
+ (BOOL)resolveInstanceMethod:(SEL)sel {
const GPBDescriptor *descriptor = [self descriptor];
if (!descriptor) {
return [super resolveInstanceMethod:sel];
}
// NOTE: hasOrCountSel_/setHasSel_ will be NULL if the field for the given
// message should not have has support (done in GPBDescriptor.m), so there is
// no need for checks here to see if has*/setHas* are allowed.
ResolveIvarAccessorMethodResult result = {NULL, NULL};
// See comment about __unsafe_unretained on ResolveIvarGet.
for (__unsafe_unretained GPBFieldDescriptor *field in descriptor->fields_) {
BOOL isMapOrArray = GPBFieldIsMapOrArray(field);
if (!isMapOrArray) {
// Single fields.
if (sel == field->getSel_) {
ResolveIvarGet(field, &result);
const char *selName = sel_getName(sel);
const size_t selNameLength = strlen(selName);
// A setter has a leading 's' and a trailing ':' (e.g. 'setFoo:' or 'setHasFoo:').
BOOL couldBeSetter = selName[0] == 's' && selName[selNameLength - 1] == ':';
if (couldBeSetter) {
// See comment about __unsafe_unretained on ResolveIvarGet.
for (__unsafe_unretained GPBFieldDescriptor *field in descriptor->fields_) {
BOOL isMapOrArray = GPBFieldIsMapOrArray(field);
if (GPBIsSetSelForField(selName, selNameLength, field)) {
if (isMapOrArray) {
// Local for syntax so the block can directly capture it and not the
// full lookup.
result.impToAdd = imp_implementationWithBlock(^(id obj, id value) {
GPBSetObjectIvarWithFieldPrivate(obj, field, value);
});
result.encodingSelector = @selector(setArray:);
} else {
ResolveIvarSet(field, &result);
}
break;
} else if (sel == field->setSel_) {
ResolveIvarSet(field, &result);
break;
} else if (sel == field->hasOrCountSel_) {
int32_t index = GPBFieldHasIndex(field);
uint32_t fieldNum = GPBFieldNumber(field);
result.impToAdd = imp_implementationWithBlock(^(id obj) {
return GPBGetHasIvar(obj, index, fieldNum);
});
result.encodingSelector = @selector(getBool);
break;
} else if (sel == field->setHasSel_) {
} else if (!isMapOrArray && GPBIsSetHasSelForField(selName, selNameLength, field)) {
result.impToAdd = imp_implementationWithBlock(^(id obj, BOOL value) {
if (value) {
[NSException raise:NSInvalidArgumentException
format:@"%@: %@ can only be set to NO (to clear field).", [obj class],
NSStringFromSelector(field->setHasSel_)];
NSStringFromSelector(sel)];
}
GPBClearMessageField(obj, field);
});
result.encodingSelector = @selector(setBool:);
break;
} else {
GPBOneofDescriptor *oneof = field->containingOneof_;
if (oneof && (sel == oneof->caseSel_)) {
}
}
} else {
// See comment about __unsafe_unretained on ResolveIvarGet.
for (__unsafe_unretained GPBFieldDescriptor *field in descriptor->fields_) {
BOOL isMapOrArray = GPBFieldIsMapOrArray(field);
if (GPBIsGetSelForField(selName, field)) {
if (isMapOrArray) {
if (field.fieldType == GPBFieldTypeRepeated) {
result.impToAdd = imp_implementationWithBlock(^(id obj) {
return GetArrayIvarWithField(obj, field);
});
} else {
result.impToAdd = imp_implementationWithBlock(^(id obj) {
return GetMapIvarWithField(obj, field);
});
}
result.encodingSelector = @selector(getArray);
} else {
ResolveIvarGet(field, &result);
}
break;
}
if (!isMapOrArray) {
if (GPBIsHasSelForField(selName, selNameLength, field)) {
int32_t index = GPBFieldHasIndex(field);
uint32_t fieldNum = GPBFieldNumber(field);
result.impToAdd = imp_implementationWithBlock(^(id obj) {
return GPBGetHasOneof(obj, index);
return GPBGetHasIvar(obj, index, fieldNum);
});
result.encodingSelector = @selector(getEnum);
result.encodingSelector = @selector(getBool);
break;
} else {
GPBOneofDescriptor *oneof = field->containingOneof_;
if (oneof && GPBIsCaseOfSelForOneOf(selName, selNameLength, oneof)) {
int32_t index = GPBFieldHasIndex(field);
result.impToAdd = imp_implementationWithBlock(^(id obj) {
return GPBGetHasOneof(obj, index);
});
result.encodingSelector = @selector(getEnum);
break;
}
}
} else {
if (GPBIsCountSelForField(selName, selNameLength, field)) {
result.impToAdd = imp_implementationWithBlock(^(id obj) {
// Type doesn't matter, all *Array and *Dictionary types support
// -count.
NSArray *arrayOrMap = GPBGetObjectIvarWithFieldNoAutocreate(obj, field);
return [arrayOrMap count];
});
result.encodingSelector = @selector(getArrayCount);
break;
}
}
} else {
// map<>/repeated fields.
if (sel == field->getSel_) {
if (field.fieldType == GPBFieldTypeRepeated) {
result.impToAdd = imp_implementationWithBlock(^(id obj) {
return GetArrayIvarWithField(obj, field);
});
} else {
result.impToAdd = imp_implementationWithBlock(^(id obj) {
return GetMapIvarWithField(obj, field);
});
}
result.encodingSelector = @selector(getArray);
break;
} else if (sel == field->setSel_) {
// Local for syntax so the block can directly capture it and not the
// full lookup.
result.impToAdd = imp_implementationWithBlock(^(id obj, id value) {
GPBSetObjectIvarWithFieldPrivate(obj, field, value);
});
result.encodingSelector = @selector(setArray:);
break;
} else if (sel == field->hasOrCountSel_) {
result.impToAdd = imp_implementationWithBlock(^(id obj) {
// Type doesn't matter, all *Array and *Dictionary types support
// -count.
NSArray *arrayOrMap = GPBGetObjectIvarWithFieldNoAutocreate(obj, field);
return [arrayOrMap count];
});
result.encodingSelector = @selector(getArrayCount);
break;
}
}
}
if (result.impToAdd) {
const char *encoding = GPBMessageEncodingForSelector(result.encodingSelector, YES);
Class msgClass = descriptor.messageClass;

9
objectivec/GPBUtilities.m
View File

@ -539,16 +539,17 @@ void GPBSetRetainedObjectIvarWithFieldPrivate(GPBMessage *self, GPBFieldDescript
// field, and fall back on the default value. The warning below will only
// appear in debug, but the could should be changed so the intention is
// clear.
NSString *hasSel = NSStringFromSelector(field->hasOrCountSel_);
NSString *propName = field.name;
NSString *className = self.descriptor.name;
NSString *firstLetterCapitalizedName = [[[className substringToIndex:1] uppercaseString]
stringByAppendingString:[className substringFromIndex:1]];
NSLog(@"warning: '%@.%@ = nil;' is not clearly defined for fields with "
@"default values. Please use '%@.%@ = %@' if you want to set it to "
@"empty, or call '%@.%@ = NO' to reset it to it's default value of "
@"empty, or call '%@.has%@ = NO' to reset it to it's default value of "
@"'%@'. Defaulting to resetting default value.",
className, propName, className, propName,
(fieldType == GPBDataTypeString) ? @"@\"\"" : @"GPBEmptyNSData()", className, hasSel,
field.defaultValue.valueString);
(fieldType == GPBDataTypeString) ? @"@\"\"" : @"GPBEmptyNSData()", className,
firstLetterCapitalizedName, field.defaultValue.valueString);
// Note: valueString, depending on the type, it could easily be
// valueData/valueMessage.
}