From ac914490435f1e070c609c2a2a219a4322e5515e Mon Sep 17 00:00:00 2001 From: Lars Wirzenius Date: Sat, 5 Mar 2011 14:54:06 +0000 Subject: Add stuff. --- lib/dynstr.c | 547 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 547 insertions(+) create mode 100644 lib/dynstr.c (limited to 'lib/dynstr.c') diff --git a/lib/dynstr.c b/lib/dynstr.c new file mode 100644 index 0000000..44c4b56 --- /dev/null +++ b/lib/dynstr.c @@ -0,0 +1,547 @@ +/* + * dynstr.c - implement dynamic byte strings + * Copyright 2010 Lars Wirzenius + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + */ + + +/* We shamelessly use GNU extensions to the standard C library. + * Primarily this is the memmem(3) function. Patches are welcome to + * get rid of this, but I did not feel like re-inventing the wheel. + */ +#define _GNU_SOURCE + +#include +#include +#include +#include +#include + +#include "dynstr.h" + + +/* This is how the dynamic strings are represented. */ +struct Dynstr { + unsigned char *mem; + size_t size; +}; + + +/* Return value for readline_helper's callback functions. */ +#define DYNSTR_ERROR ((size_t) -1) + + +/* The current malloc and malloc error handler functions. */ +static dynstr_error_handler *error_handler = dynstr_malloc_error_indicate; +static void *(*current_malloc)(size_t) = malloc; + + +void dynstr_init(void) +{ + error_handler = dynstr_malloc_error_indicate; + current_malloc = malloc; +} + + +void *(*dynstr_get_malloc(void))(size_t) +{ + return current_malloc; +} + + +void dynstr_set_malloc(void *(*new_malloc)(size_t)) +{ + current_malloc = new_malloc; +} + + +dynstr_error_handler *dynstr_get_malloc_error_handler(void) +{ + return error_handler; +} + + +void dynstr_set_malloc_error_handler(dynstr_error_handler *handler) +{ + error_handler = handler; +} + + +void dynstr_malloc_error_indicate(int error, size_t size, void *oldptr) +{ +} + +void dynstr_malloc_error_abort(int error, size_t size, void *oldptr) +{ + abort(); +} + + +/* Dynamically allocate a number of bytes. Call error handler if necessary. */ +static void *alloc(size_t size) +{ + void *p; + + p = current_malloc(size); + if (p == NULL) + error_handler(errno, size, NULL); + return p; +} + + +static Dynstr *new_dynstr(const void *mem, size_t size, bool dynamic) +{ + Dynstr *dynstr; + + if (dynamic) { + dynstr = alloc(sizeof(Dynstr) + size); + if (dynstr == NULL) + return NULL; + dynstr->mem = ((unsigned char *) dynstr) + sizeof(Dynstr); + } else { + dynstr = alloc(sizeof(Dynstr)); + if (dynstr == NULL) + return NULL; + dynstr->mem = (unsigned char *) mem; + } + + dynstr->size = size; + return dynstr; +} + + +static void init_dynstr(Dynstr *dynstr, const void *mem, bool dynamic) +{ + if (dynamic) + memcpy(dynstr->mem, mem, dynstr->size); +} + + +/* Allocate a new dynamic string. If dynamic is true, the contents of the + * new string is copied from mem. Otherwise the new string just uses mem + * directly. */ +static Dynstr *newstr(const void *mem, size_t size, bool dynamic) +{ + Dynstr *dynstr; + + dynstr = new_dynstr(mem, size, dynamic); + if (dynstr != NULL) + init_dynstr(dynstr, mem, dynamic); + return dynstr; +} + + +Dynstr *dynstr_new_empty(void) +{ + return new_dynstr(NULL, 0, false); +} + + +Dynstr *dynstr_new_from_cstring(const char *cstring) +{ + return newstr(cstring, strlen(cstring), true); +} + + +Dynstr *dynstr_new_from_memory(const void *mem, size_t size) +{ + return newstr(mem, size, true); +} + + +Dynstr *dynstr_new_from_constant_cstring(const char *cstring) +{ + return newstr(cstring, strlen(cstring), false); +} + + +Dynstr *dynstr_new_from_constant_memory(const void *mem, size_t size) +{ + return newstr(mem, size, false); +} + + +void dynstr_free(Dynstr *dynstr) +{ + free(dynstr); +} + + +size_t dynstr_len(Dynstr *dynstr) +{ + return dynstr->size; +} + + +bool dynstr_is_empty(Dynstr *dynstr) +{ + return dynstr_len(dynstr) == 0; +} + + +size_t dynstr_memcpy(void *mem, Dynstr *dynstr, size_t offset, size_t size) +{ + size_t len; + + len = dynstr_len(dynstr); + if (offset >= len) + return 0; + if (size > len - offset) + size = len - offset; + memcpy(mem, dynstr->mem + offset, size); + return size; +} + + +char *dynstr_strdup(Dynstr *dynstr) +{ + char *mem; + + mem = alloc(dynstr->size + 1); + if (mem == NULL) + return NULL; + memcpy(mem, dynstr->mem, dynstr->size); + mem[dynstr->size] = '\0'; + return mem; +} + + +Dynstr *dynstr_substr(Dynstr *dynstr, size_t offset, size_t size) +{ + if (offset >= dynstr->size) { + offset = 0; + size = 0; + } else if (size > dynstr->size - offset) { + size = dynstr->size - offset; + } + return newstr(dynstr->mem + offset, size, true); +} + + +Dynstr *dynstr_cat(Dynstr *dynstr1, Dynstr *dynstr2) +{ + return dynstr_cat_many(dynstr1, dynstr2, (Dynstr *) NULL); +} + + +Dynstr *dynstr_cat_many(Dynstr *dynstr, ...) +{ + va_list args; + Dynstr *result; + size_t size; + size_t offset; + + va_start(args, dynstr); + size = 0; + for (Dynstr *p = dynstr; p != NULL; p = va_arg(args, Dynstr *)) + size += p->size; + va_end(args); + + result = new_dynstr(NULL, size, true); + if (result == NULL) + return NULL; + + va_start(args, dynstr); + offset = 0; + for (Dynstr *p = dynstr; p != NULL; p = va_arg(args, Dynstr *)) { + memcpy(result->mem + offset, p->mem, p->size); + offset += p->size; + } + va_end(args); + + return result; +} + + +int dynstr_byte_at(Dynstr *dynstr, size_t offset) +{ + if (offset >= dynstr->size) + return -1; + return dynstr->mem[offset]; +} + + +size_t dynstr_first_byte(Dynstr *dynstr, size_t offset, int byte) +{ + unsigned char *p; + + if (offset >= dynstr->size) + return DYNSTR_NOT_FOUND; + p = memchr(dynstr->mem + offset, byte, dynstr->size - offset); + if (p == NULL) + return DYNSTR_NOT_FOUND; + return (size_t) (p - dynstr->mem); +} + + +size_t dynstr_last_byte(Dynstr *dynstr, size_t offset, int byte) +{ + unsigned char *p; + + if (offset >= dynstr->size) + return DYNSTR_NOT_FOUND; + p = memrchr(dynstr->mem + offset, byte, dynstr->size - offset); + if (p == NULL) + return DYNSTR_NOT_FOUND; + return (size_t) (p - dynstr->mem); +} + + +size_t dynstr_first_string(Dynstr *dynstr, size_t offset, Dynstr *pattern) +{ + const unsigned char *p; + + if (offset >= dynstr->size) + return DYNSTR_NOT_FOUND; + if (pattern->size == 0) + return DYNSTR_NOT_FOUND; + p = memmem(dynstr->mem + offset, dynstr->size - offset, + pattern->mem, pattern->size); + if (p == NULL) + return DYNSTR_NOT_FOUND; + return (size_t) (p - dynstr->mem); +} + + +size_t dynstr_last_string(Dynstr *dynstr, size_t offset, Dynstr *pattern) +{ + size_t result; + size_t new_result; + + /* GNU libc lacks a memrmem function, so we loop to the last + * dynstr_first_string match. */ + result = DYNSTR_NOT_FOUND; + for (;;) { + new_result = dynstr_first_string(dynstr, offset, pattern); + if (new_result == DYNSTR_NOT_FOUND) + break; + result = new_result; + offset = result + 1; + } + return result; +} + + +int dynstr_cmp(Dynstr *dynstr1, Dynstr *dynstr2) +{ + int result; + size_t min_size; + + if (dynstr1->size < dynstr2->size) + min_size = dynstr1->size; + else + min_size = dynstr2->size; + result = memcmp(dynstr1->mem, dynstr2->mem, min_size); + if (result == 0) { + if (dynstr1->size < dynstr2->size) + return -1; + else if (dynstr1->size == dynstr2->size) + return 0; + else + return 1; + } + return result; +} + + +size_t dynstr_fwrite(FILE *file, Dynstr *dynstr) +{ + return fwrite(dynstr->mem, 1, dynstr->size, file); +} + + +ssize_t dynstr_write(int fd, Dynstr *dynstr) +{ + return write(fd, dynstr->mem, dynstr->size); +} + + +/* A helper function for dynstr_read and dynstr_fread. The callback does + * the actual reading. */ +static Dynstr *read_helper(size_t (*callback)(FILE *f, int fd, unsigned char *buf, + size_t size), + FILE *f, int fd, size_t size) +{ + Dynstr *dynstr; + Dynstr *dynstr2; + size_t n; + + dynstr = new_dynstr(NULL, size, true); + if (dynstr == NULL) + return NULL; + + n = callback(f, fd, dynstr->mem, size); + if (n == DYNSTR_ERROR) { + dynstr_free(dynstr); + return NULL; + } + + if (n < size) { + dynstr2 = dynstr_substr(dynstr, 0, n); + if (dynstr2 == NULL) { + dynstr->size = n; + } else { + dynstr_free(dynstr); + dynstr = dynstr2; + } + } + + return dynstr; +} + + +static size_t fread_callback(FILE *f, int fd, unsigned char *buf, size_t size) +{ + size_t n; + + n = fread(buf, 1, size, f); + if (n == 0 && ferror(f)) + return DYNSTR_ERROR; + return n; +} + + +static size_t read_callback(FILE *f, int fd, unsigned char *buf, size_t size) +{ + ssize_t n; + + do { + n = read(fd, buf, size); + } while (n == -1 && errno == EINTR); + if (n == -1) + return DYNSTR_ERROR; + return n; +} + + +Dynstr *dynstr_fread(FILE *file, size_t size) +{ + return read_helper(fread_callback, file, -1, size); +} + + +Dynstr *dynstr_read(int file, size_t size) +{ + return read_helper(read_callback, NULL, file, size); +} + + +/* Helper function for dynstr_readline and dynstr_freadline. The callback + * does the actual reading. Reading happens one byte at a time, since we + * must not read past the newline that terminates a line. */ +static Dynstr *readline_helper(int (*callback)(FILE *, int), FILE *f, int fd) +{ + Dynstr *line; + Dynstr *temp1; + Dynstr *temp2; + int c; + unsigned char buf[1024]; + size_t buflen; + + line = dynstr_new_empty(); + buflen = 0; + + for (;;) { + temp1 = NULL; + temp2 = NULL; + + c = callback(f, fd); + if (c == -1) + goto error; + else if (c == -2) + break; + + buf[buflen++] = c; + if (buflen == sizeof(buf)) { + temp1 = dynstr_new_from_constant_memory(buf, buflen); + if (temp1 == NULL) + goto error; + temp2 = dynstr_cat(line, temp1); + if (temp2 == NULL) + goto error; + dynstr_free(temp1); + dynstr_free(line); + line = temp2; + buflen = 0; + } + + if (c == '\n') + break; + } + + if (buflen > 0) { + temp1 = dynstr_new_from_constant_memory(buf, buflen); + if (temp1 == NULL) + goto error; + temp2 = dynstr_cat(line, temp1); + if (temp2 == NULL) + goto error; + dynstr_free(temp1); + dynstr_free(line); + line = temp2; + } + + return line; + +error: + dynstr_free(line); + dynstr_free(temp1); + dynstr_free(temp2); + return NULL; +} + + +static int freadline_callback(FILE *f, int fd) +{ + int c; + + c = getc(f); + if (c == EOF && ferror(f)) + return -1; + else if (c == EOF) + return -2; + else + return c; +} + + +Dynstr *dynstr_freadline(FILE *file) +{ + return readline_helper(freadline_callback, file, -1); +} + + +static int readline_callback(FILE *f, int fd) +{ + unsigned char c; + int n; + + do { + n = read(fd, &c, 1); + } while (n == -1 && errno == EINTR); + if (n == 0) + return -2; + else if (n == -1) + return -1; + else + return c; +} + + +Dynstr *dynstr_readline(int file) +{ + return readline_helper(readline_callback, NULL, file); +} + -- cgit v1.2.1