Telodendria/src/Config.c
2022-07-22 20:19:12 -04:00

452 lines
11 KiB
C

#include <Config.h>
#include <stdlib.h>
#include <ctype.h>
#include <string.h>
#ifndef CONFIG_BUFFER_BLOCK
#define CONFIG_BUFFER_BLOCK 32
#endif
struct ConfigDirective {
Array *values;
HashMap *children;
};
struct ConfigParseResult {
unsigned int ok : 1;
union {
size_t lineNumber;
HashMap *confMap;
} data;
};
typedef enum ConfigToken {
TOKEN_UNKNOWN,
TOKEN_NAME,
TOKEN_MACRO_ASSIGNMENT,
TOKEN_VALUE,
TOKEN_SEMICOLON,
TOKEN_BLOCK_OPEN,
TOKEN_BLOCK_CLOSE,
TOKEN_MACRO,
TOKEN_EOF
} ConfigToken;
typedef struct ConfigParserState {
FILE *stream;
unsigned int line;
char *token;
size_t tokenSize;
size_t tokenLen;
ConfigToken tokenType;
HashMap *macroMap;
} ConfigParserState;
unsigned int
ConfigParseResultOk(ConfigParseResult *result)
{
return result ? result->ok : 0;
}
size_t
ConfigParseResultLineNumber(ConfigParseResult *result)
{
return result && !result->ok ? result->data.lineNumber : 0;
}
HashMap *
ConfigParseResultGet(ConfigParseResult *result)
{
return result && result->ok ? result->data.confMap : NULL;
}
void
ConfigParseResultFree(ConfigParseResult *result)
{
/*
* Note that if the parse was valid, the hash map
* needs to be freed separately.
*/
free(result);
}
Array *
ConfigValuesGet(ConfigDirective *directive)
{
return directive ? directive->values : NULL;
}
HashMap *
ConfigChildrenGet(ConfigDirective *directive)
{
return directive ? directive->children : NULL;
}
/*
* Takes a void pointer because it is only used with
* HashMapIterate(), which requires a pointer to a function
* that takes a void pointer.
*/
static void
ConfigDirectiveFree(void *ptr)
{
ConfigDirective *directive = ptr;
size_t i;
if (!directive)
{
return;
}
for (i = 0; i < ArraySize(directive->values); i++)
{
free(ArrayGet(directive->values, i));
}
ArrayFree(directive->values);
ConfigFree(directive->children);
free(directive);
}
void
ConfigFree(HashMap *conf)
{
HashMapIterate(conf, ConfigDirectiveFree);
HashMapFree(conf);
}
static ConfigParserState *
ConfigParserStateCreate(FILE * stream)
{
ConfigParserState *state = malloc(sizeof(ConfigParserState));
if (!state)
{
return NULL;
}
state->macroMap = HashMapCreate();
if (!state->macroMap)
{
free(state);
return NULL;
}
state->stream = stream;
state->line = 1;
state->token = NULL;
state->tokenSize = 0;
state->tokenLen = 0;
state->tokenType = TOKEN_UNKNOWN;
return state;
}
static void
ConfigParserStateFree(ConfigParserState *state)
{
if (!state)
{
return;
}
free(state->token);
HashMapIterate(state->macroMap, free);
HashMapFree(state->macroMap);
free(state);
}
static int
ConfigIsNameChar(int c)
{
return isdigit(c) || isalpha(c) || (c == '-' || c == '_');
}
static char
ConfigConsumeWhitespace(ConfigParserState *state)
{
int c;
while (isspace(c = fgetc(state->stream)))
{
if (c == '\n')
{
state->line++;
}
}
return c;
}
static void
ConfigConsumeLine(ConfigParserState *state)
{
while (fgetc(state->stream) != '\n');
state->line++;
}
static void
ConfigTokenSeek(ConfigParserState *state)
{
int c;
/* If we already hit EOF, don't do anything */
if (state->tokenType == TOKEN_EOF) {
return;
}
while ((c = ConfigConsumeWhitespace(state)) == '#') {
ConfigConsumeLine(state);
}
/*
* After all whitespace and comments are consumed, identify the
* token by looking at the next character
*/
if (feof(state->stream)) {
state->tokenType = TOKEN_EOF;
return;
}
if (ConfigIsNameChar(c)) {
state->tokenLen = 0;
/* Read the key/macro into state->token */
if (!state->token) {
state->tokenSize = CONFIG_BUFFER_BLOCK;
state->token = malloc(CONFIG_BUFFER_BLOCK);
}
state->token[state->tokenLen] = c;
state->tokenLen++;
while (ConfigIsNameChar((c = fgetc(state->stream)))) {
state->token[state->tokenLen] = c;
state->tokenLen++;
if (state->tokenLen >= state->tokenSize) {
state->tokenSize += CONFIG_BUFFER_BLOCK;
state->token = realloc(state->token,
state->tokenSize);
}
}
state->token[state->tokenLen] = '\0';
state->tokenLen++;
if (!isspace(c)) {
state->tokenType = TOKEN_UNKNOWN;
} else {
state->tokenType = TOKEN_NAME;
if (c == '\n') {
state->line++;
}
}
} else {
switch (c) {
case '=':
state->tokenType = TOKEN_MACRO_ASSIGNMENT;
break;
case '"':
state->tokenLen = 0;
state->tokenType = TOKEN_VALUE;
/* read the value into state->curtok */
while ((c = fgetc(state->stream)) != '"') {
if (c == '\n') {
state->line++;
}
/*
* End of the stream reached without finding
* a closing quote
*/
if (feof(state->stream)) {
state->tokenType = TOKEN_EOF;
break;
}
state->token[state->tokenLen] = c;
state->tokenLen++;
if (state->tokenLen >= state->tokenSize) {
state->tokenSize += CONFIG_BUFFER_BLOCK;
state->token = realloc(state->token,
state->tokenSize);
}
}
state->token[state->tokenLen] = '\0';
state->tokenLen++;
break;
case ';':
state->tokenType = TOKEN_SEMICOLON;
break;
case '{':
state->tokenType = TOKEN_BLOCK_OPEN;
break;
case '}':
state->tokenType = TOKEN_BLOCK_CLOSE;
break;
case '$':
state->tokenLen = 0;
/* read the macro name into state->curtok */
while (ConfigIsNameChar(c = fgetc(state->stream))) {
state->token[state->tokenLen] = c;
state->tokenLen++;
if (state->tokenLen >= state->tokenSize) {
state->tokenSize += CONFIG_BUFFER_BLOCK;
state->token = realloc(state->token,
state->tokenSize);
}
}
state->token[state->tokenLen] = '\0';
state->tokenLen++;
state->tokenType = TOKEN_MACRO;
ungetc(c, state->stream);
break;
default:
state->tokenType = TOKEN_UNKNOWN;
break;
}
}
/* Resize curtok to only use the bytes it needs */
if (state->tokenLen) {
state->tokenSize = state->tokenLen;
state->token = realloc(state->token, state->tokenSize);
}
}
static int
ConfigExpect(ConfigParserState *state, ConfigToken tokenType)
{
return state->tokenType == tokenType;
}
static HashMap *
ConfigParseBlock(ConfigParserState *state, int level)
{
HashMap *block = HashMapCreate();
ConfigTokenSeek(state);
while (ConfigExpect(state, TOKEN_NAME)) {
char *name = malloc(state->tokenLen + 1);
strcpy(name, state->token);
ConfigTokenSeek(state);
if (ConfigExpect(state, TOKEN_VALUE) || ConfigExpect(state, TOKEN_MACRO)) {
ConfigDirective *directive;
directive = malloc(sizeof(ConfigDirective));
directive->children = NULL;
directive->values = ArrayCreate();
while (ConfigExpect(state, TOKEN_VALUE) ||
ConfigExpect(state, TOKEN_MACRO)) {
char *dval;
char *dvalCpy;
if (ConfigExpect(state, TOKEN_VALUE)) {
dval = state->token;
} else if (ConfigExpect(state, TOKEN_MACRO)) {
dval = HashMapGet(state->macroMap, state->token);
if (!dval) {
goto error;
}
} else {
dval = NULL; /* Should never happen */
}
/* dval is a pointer which is overwritten with the next token. */
dvalCpy = malloc(strlen(dval) + 1);
strcpy(dvalCpy, dval);
ArrayAdd(directive->values, dvalCpy);
ConfigTokenSeek(state);
}
if (ConfigExpect(state, TOKEN_BLOCK_OPEN)) {
/* token_seek(state); */
directive->children = ConfigParseBlock(state, level + 1);
if (!directive->children) {
goto error;
}
}
/*
* Append this directive to the current block,
* overwriting a directive at this level with the same name.
*
* Note that if a value already exists with this name, it is
* returned by HashMapSet() and then immediately passed to
* ConfigDirectiveFree(). If the value does not exist, then
* NULL is sent to ConfigDirectiveFree(), making it a no-op.
*/
ConfigDirectiveFree(HashMapSet(block, name, directive));
} else if (ConfigExpect(state, TOKEN_MACRO_ASSIGNMENT)) {
ConfigTokenSeek(state);
if (ConfigExpect(state, TOKEN_VALUE)) {
char * valueCopy = malloc(strlen(state->token) + 1);
strcpy(valueCopy, state->token);
free(HashMapSet(state->macroMap, name, state->token));
ConfigTokenSeek(state);
} else {
goto error;
}
} else {
goto error;
}
if (!ConfigExpect(state, TOKEN_SEMICOLON)) {
goto error;
}
ConfigTokenSeek(state);
}
if (ConfigExpect(state, level ? TOKEN_BLOCK_CLOSE : TOKEN_EOF)) {
ConfigTokenSeek(state);
return block;
} else {
goto error;
}
error:
/* Only free the very top level, because this will recurse */
if (!level) {
ConfigFree(block);
}
return NULL;
}
ConfigParseResult *
ConfigParse(FILE * stream)
{
ConfigParseResult *result;
HashMap *conf;
ConfigParserState *state;
result = malloc(sizeof(ConfigParseResult));
state = ConfigParserStateCreate(stream);
conf = ConfigParseBlock(state, 0);
if (!conf) {
result->ok = 0;
result->data.lineNumber = state->line;
} else {
result->ok = 1;
result->data.confMap = conf;
}
ConfigParserStateFree(state);
return result;
}