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Diffstat (limited to 'Source/SPJSONFormatter.m')
| -rw-r--r-- | Source/SPJSONFormatter.m | 364 |
1 files changed, 364 insertions, 0 deletions
diff --git a/Source/SPJSONFormatter.m b/Source/SPJSONFormatter.m new file mode 100644 index 00000000..05cc2992 --- /dev/null +++ b/Source/SPJSONFormatter.m @@ -0,0 +1,364 @@ +// +// SPJSONFormatter.m +// sequel-pro +// +// Created by Max Lohrmann on 10.02.17. +// Copyright (c) 2017 Max Lohrmann. All rights reserved. +// +// Permission is hereby granted, free of charge, to any person +// obtaining a copy of this software and associated documentation +// files (the "Software"), to deal in the Software without +// restriction, including without limitation the rights to use, +// copy, modify, merge, publish, distribute, sublicense, and/or sell +// copies of the Software, and to permit persons to whom the +// Software is furnished to do so, subject to the following +// conditions: +// +// The above copyright notice and this permission notice shall be +// included in all copies or substantial portions of the Software. +// +// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, +// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES +// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND +// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT +// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, +// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING +// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR +// OTHER DEALINGS IN THE SOFTWARE. +// +// More info at <https://github.com/sequelpro/sequelpro> + +#import "SPJSONFormatter.h" + + +static char GetNextANSIChar(SPJSONTokenizerState *stateInfo); + + +@implementation SPJSONFormatter + ++ (NSString *)stringByFormattingString:(NSString *)input +{ + SPJSONTokenizerState stateInfo; + if(SPJSONTokenizerInit(input,&stateInfo) == -1) return nil; + + NSUInteger idLevel = 0; + + NSCharacterSet *wsNlCharset = [NSCharacterSet whitespaceAndNewlineCharacterSet]; + NSMutableString *formatted = [[NSMutableString alloc] init]; + + SPJSONToken prevTokenType = JSON_TOK_EOF; + SPJSONTokenInfo curToken; + if(SPJSONTokenizerGetNextToken(&stateInfo,&curToken) == -1) { + [formatted release]; + return nil; + } + + BOOL needIndent = NO; + SPJSONTokenInfo nextToken; + do { + //we need to know the next token to do meaningful formatting + if(SPJSONTokenizerGetNextToken(&stateInfo,&nextToken) == -1) { + [formatted release]; + return nil; + } + + if(curToken.tok == JSON_TOK_SQUARE_BRACE_CLOSE || curToken.tok == JSON_TOK_CURLY_BRACE_CLOSE) + idLevel--; + + //if this token is a "]" or "}" and there was no "[" or "{" directly before it, add a linebreak before + if(prevTokenType != JSON_TOK_CURLY_BRACE_OPEN && prevTokenType != JSON_TOK_SQUARE_BRACE_OPEN && (curToken.tok == JSON_TOK_SQUARE_BRACE_CLOSE || curToken.tok == JSON_TOK_CURLY_BRACE_CLOSE)) { + [formatted appendString:@"\n"]; + needIndent = YES; + } + + //if this token is on a new line indent it + if(needIndent && idLevel > 0) { + //32 tabs pool (with fallback for even deeper nesting) + static NSString *tabs = @"\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t"; + NSUInteger myIdLevel = idLevel; + while(myIdLevel > [tabs length]) { + [formatted appendString:tabs]; + myIdLevel -= [tabs length]; + } + [formatted appendString:[tabs substringWithRange:NSMakeRange(0, myIdLevel)]]; + needIndent = NO; + } + + //save ourselves the overhead of creating an NSString if we already know what it will contain + NSString *curTokenString; + id freeMe = nil; + switch (curToken.tok) { + case JSON_TOK_CURLY_BRACE_OPEN: + curTokenString = @"{"; + break; + + case JSON_TOK_CURLY_BRACE_CLOSE: + curTokenString = @"}"; + break; + + case JSON_TOK_SQUARE_BRACE_OPEN: + curTokenString = @"["; + break; + + case JSON_TOK_SQUARE_BRACE_CLOSE: + curTokenString = @"]"; + break; + + case JSON_TOK_DOUBLE_QUOTE: + curTokenString = @"\""; + break; + + case JSON_TOK_COLON: + curTokenString = @": "; //add a space after ":" for readability + break; + + case JSON_TOK_COMMA: + curTokenString = @","; + break; + + //JSON_TOK_OTHER + //JSON_TOK_STRINGDATA + default: + curTokenString = [[NSString alloc] initWithBytesNoCopy:(void *)(&stateInfo.str[curToken.pos]) length:curToken.len encoding:NSUTF8StringEncoding freeWhenDone:NO]; + //for everything except strings get rid of surrounding whitespace + if(curToken.tok != JSON_TOK_STRINGDATA) { + NSString *newTokenString = [[curTokenString stringByTrimmingCharactersInSet:wsNlCharset] retain]; + [curTokenString release]; + curTokenString = newTokenString; + } + freeMe = curTokenString; + } + + [formatted appendString:curTokenString]; + + if(freeMe) [freeMe release]; + + //if the current token is a "[", "{" or "," and the next token is not a "]" or "}" add a line break afterwards + if( + curToken.tok == JSON_TOK_COMMA || + (curToken.tok == JSON_TOK_CURLY_BRACE_OPEN && nextToken.tok != JSON_TOK_CURLY_BRACE_CLOSE) || + (curToken.tok == JSON_TOK_SQUARE_BRACE_OPEN && nextToken.tok != JSON_TOK_SQUARE_BRACE_CLOSE) + ) { + [formatted appendString:@"\n"]; + needIndent = YES; + } + + if(curToken.tok == JSON_TOK_CURLY_BRACE_OPEN || curToken.tok == JSON_TOK_SQUARE_BRACE_OPEN) + idLevel++; + + prevTokenType = curToken.tok; + curToken = nextToken; + } while(curToken.tok != JSON_TOK_EOF); //SPJSONTokenizerGetNextToken() will always return JSON_TOK_EOF once it has reached that state + + return [formatted autorelease]; +} + ++ (NSString *)stringByUnformattingString:(NSString *)input +{ + SPJSONTokenizerState stateInfo; + if(SPJSONTokenizerInit(input,&stateInfo) == -1) return nil; + + NSCharacterSet *wsNlCharset = [NSCharacterSet whitespaceAndNewlineCharacterSet]; + NSMutableString *unformatted = [[NSMutableString alloc] init]; + + do { + SPJSONTokenInfo curToken; + if(SPJSONTokenizerGetNextToken(&stateInfo,&curToken) == -1) { + [unformatted release]; + return nil; + } + + if(curToken.tok == JSON_TOK_EOF) break; + + //save ourselves the overhead of creating an NSString from input if we already know what it will contain + NSString *curTokenString; + id freeMe = nil; + switch (curToken.tok) { + case JSON_TOK_CURLY_BRACE_OPEN: + curTokenString = @"{"; + break; + + case JSON_TOK_CURLY_BRACE_CLOSE: + curTokenString = @"}"; + break; + + case JSON_TOK_SQUARE_BRACE_OPEN: + curTokenString = @"["; + break; + + case JSON_TOK_SQUARE_BRACE_CLOSE: + curTokenString = @"]"; + break; + + case JSON_TOK_DOUBLE_QUOTE: + curTokenString = @"\""; + break; + + case JSON_TOK_COLON: + curTokenString = @": "; //add a space after ":" to match MySQL + break; + + case JSON_TOK_COMMA: + curTokenString = @", "; //add a space after "," to match MySQL + break; + + //JSON_TOK_OTHER + //JSON_TOK_STRINGDATA + default: + curTokenString = [[NSString alloc] initWithBytesNoCopy:(void *)(&stateInfo.str[curToken.pos]) length:curToken.len encoding:NSUTF8StringEncoding freeWhenDone:NO]; + //for everything except strings get rid of surrounding whitespace + if(curToken.tok != JSON_TOK_STRINGDATA) { + NSString *newTokenString = [[curTokenString stringByTrimmingCharactersInSet:wsNlCharset] retain]; + [curTokenString release]; + curTokenString = newTokenString; + } + freeMe = curTokenString; + } + + [unformatted appendString:curTokenString]; + + if(freeMe) [freeMe release]; + + } while(1); + + return [unformatted autorelease]; +} + + +@end + +/** + * This function returns the char at the current position in the input string and forwards the read pointer to the next char. + * If the character is part of an UTF8 multibyte sequence, the function will skip forward until a single byte character is found again + * or EOF is reached (whichever comes first). + * + * stateInfo MUST be valid or this will crash! + * + * @return Either a char in the range 0-127 or -1 if EOF is reached. + */ +char GetNextANSIChar(SPJSONTokenizerState *stateInfo) { + do { + if(stateInfo->pos >= stateInfo->len) + return -1; + char val = stateInfo->str[stateInfo->pos++]; + // all utf8 multibyte characters start with the most significant bit being 1 for all of their bytes + // but since all JSON control characters are in the single byte ANSI compatible plane, we can just ignore any MB chars + if((val & 0x80) == 0) + return val; + } while(1); +} + +int SPJSONTokenizerInit(NSString *input, SPJSONTokenizerState *stateInfo) { + if(!input || ![input respondsToSelector:@selector(UTF8String)] || stateInfo == NULL) + return -1; + + stateInfo->ctxt = JSON_ROOT_CONTEXT; + stateInfo->pos = 0; + stateInfo->str = [input UTF8String]; + stateInfo->len = strlen(stateInfo->str); //we deem -[NSString UTF8String] to be a safe source + + return 0; +} + +int SPJSONTokenizerGetNextToken(SPJSONTokenizerState *stateInfo, SPJSONTokenInfo *tokenMatch) { + if(tokenMatch == NULL || stateInfo == NULL || stateInfo->str == NULL) + return -1; + + size_t posBefore = stateInfo->pos; + do { + char c = GetNextANSIChar(stateInfo); + if(stateInfo->ctxt == JSON_STRING_CONTEXT) { + //the only characters inside a string that are relevant to us are backslash and doublequote + if(c == '"' || c == -1) { + //if the string has contents, return that first + if((stateInfo->pos - posBefore) > 1) { + tokenMatch->tok = JSON_TOK_STRINGDATA; + tokenMatch->pos = posBefore; + if(c == '"') + stateInfo->pos--; //rewind to read it again + tokenMatch->len = stateInfo->pos - posBefore; + return 1; + } + //string is terminated by EOF (invalid JSON) + if(c == -1) { + //switch to root context and try again to reach EOF branch below + stateInfo->ctxt = JSON_ROOT_CONTEXT; + continue; + } + stateInfo->ctxt = JSON_ROOT_CONTEXT; + tokenMatch->tok = JSON_TOK_DOUBLE_QUOTE; + tokenMatch->pos = posBefore; + tokenMatch->len = stateInfo->pos - posBefore; + return 1; + } + else if(c == '\\') { + //for backslash we need to skip the next byte + // We don't care for the value of the next byte since we don't really want to parse JSON, but only format it. + // Thus we only have to pay attention to differntiate backslash-dquote and dquote. + stateInfo->pos++; + } + } + else if(c == -1) { + //if there is still unreturned input, return that first + if(posBefore < stateInfo->len) { + tokenMatch->tok = JSON_TOK_OTHER; + tokenMatch->pos = posBefore; + tokenMatch->len = stateInfo->pos - posBefore; + return 1; + } + tokenMatch->tok = JSON_TOK_EOF; + tokenMatch->pos = stateInfo->pos; //EOF sits after the last character + tokenMatch->len = 0; // EOF has no length + return 0; + } + else { + SPJSONToken tokFound = JSON_TOK_EOF; + + switch(c) { + case '"': + stateInfo->ctxt = JSON_STRING_CONTEXT; + tokFound = JSON_TOK_DOUBLE_QUOTE; + break; + + case '{': + tokFound = JSON_TOK_CURLY_BRACE_OPEN; + break; + + case '}': + tokFound = JSON_TOK_CURLY_BRACE_CLOSE; + break; + + case '[': + tokFound = JSON_TOK_SQUARE_BRACE_OPEN; + break; + + case ']': + tokFound = JSON_TOK_SQUARE_BRACE_CLOSE; + break; + + case ':': + tokFound = JSON_TOK_COLON; + break; + + case ',': + tokFound = JSON_TOK_COMMA; + break; + } + + //if we found a token, but had to walk more than 1 char there was something else + //between the previous token and this token, which we should report first + if(tokFound != JSON_TOK_EOF && (stateInfo->pos - posBefore) > 1) { + stateInfo->ctxt = JSON_ROOT_CONTEXT; + stateInfo->pos--; //rewind so we will read the token again next time + tokFound = JSON_TOK_OTHER; + } + + if(tokFound != JSON_TOK_EOF) { + tokenMatch->tok = tokFound; + tokenMatch->pos = posBefore; + tokenMatch->len = stateInfo->pos - posBefore; + return 1; + } + } + } while(1); +} |