Add stuff.

1 files changed, 547 insertions, 0 deletions

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 <http://www.gnu.org/licenses/>.
+ */
+
+
+/* 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 <errno.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#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);
+}
+