glib/gstring.c

/* GLIB - Library of useful routines for C programming
 * Copyright (C) 1995-1997  Peter Mattis, Spencer Kimball and Josh MacDonald
 * Portions Copyright (C) 1999 Tony Gale
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

/*
 * Modified by the GLib Team and others 1997-1999.  See the AUTHORS
 * file for a list of people on the GLib Team.  See the ChangeLog
 * files for a list of changes.  These files are distributed with
 * GLib at ftp://ftp.gtk.org/pub/gtk/. 
 */

/* 
 * MT safe
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <stdarg.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include "glib.h"

#define G_STRING_BLOCK_SIZE 512

typedef struct _GRealStringChunk GRealStringChunk;
typedef struct _GRealString      GRealString;

struct _GRealStringChunk
{
  GHashTable *const_table;
  GSList     *storage_list;
  gint        storage_next;
  gint        this_size;
  gint        default_size;
};

struct _GRealString
{
  gchar *str;
  gint   len;
  gint   alloc;
};

G_LOCK_DEFINE_STATIC (string_mem_chunk);
static GMemChunk *string_mem_chunk = NULL;

/* Hash Functions.
 */

gint
g_str_equal (gconstpointer v, gconstpointer v2)
{
  return strcmp ((const gchar*) v, (const gchar*)v2) == 0;
}

/* a char* hash function from ASU */
guint
g_str_hash (gconstpointer v)
{
  const char *s = (char*)v;
  const char *p;
  guint h=0, g;

  for(p = s; *p != '\0'; p += 1) {
    h = ( h << 4 ) + *p;
    if ( ( g = h & 0xf0000000 ) ) {
      h = h ^ (g >> 24);
      h = h ^ g;
    }
  }

  return h /* % M */;
}


/* String Chunks.
 */

GStringChunk*
g_string_chunk_new (gint default_size)
{
  GRealStringChunk *new_chunk = g_new (GRealStringChunk, 1);
  gint size = 1;

  while (size < default_size)
    size <<= 1;

  new_chunk->const_table       = NULL;
  new_chunk->storage_list      = NULL;
  new_chunk->storage_next      = size;
  new_chunk->default_size      = size;
  new_chunk->this_size         = size;

  return (GStringChunk*) new_chunk;
}

void
g_string_chunk_free (GStringChunk *fchunk)
{
  GRealStringChunk *chunk = (GRealStringChunk*) fchunk;
  GSList *tmp_list;

  g_return_if_fail (chunk != NULL);

  if (chunk->storage_list)
    {
      for (tmp_list = chunk->storage_list; tmp_list; tmp_list = tmp_list->next)
	g_free (tmp_list->data);

      g_slist_free (chunk->storage_list);
    }

  if (chunk->const_table)
    g_hash_table_destroy (chunk->const_table);

  g_free (chunk);
}

gchar*
g_string_chunk_insert (GStringChunk *fchunk,
		       const gchar  *string)
{
  GRealStringChunk *chunk = (GRealStringChunk*) fchunk;
  gint len = strlen (string);
  char* pos;

  g_return_val_if_fail (chunk != NULL, NULL);

  if ((chunk->storage_next + len + 1) > chunk->this_size)
    {
      gint new_size = chunk->default_size;

      while (new_size < len+1)
	new_size <<= 1;

      chunk->storage_list = g_slist_prepend (chunk->storage_list,
					     g_new (char, new_size));

      chunk->this_size = new_size;
      chunk->storage_next = 0;
    }

  pos = ((char*)chunk->storage_list->data) + chunk->storage_next;

  strcpy (pos, string);

  chunk->storage_next += len + 1;

  return pos;
}

gchar*
g_string_chunk_insert_const (GStringChunk *fchunk,
			     const gchar  *string)
{
  GRealStringChunk *chunk = (GRealStringChunk*) fchunk;
  char* lookup;

  g_return_val_if_fail (chunk != NULL, NULL);

  if (!chunk->const_table)
    chunk->const_table = g_hash_table_new (g_str_hash, g_str_equal);

  lookup = (char*) g_hash_table_lookup (chunk->const_table, (gchar *)string);

  if (!lookup)
    {
      lookup = g_string_chunk_insert (fchunk, string);
      g_hash_table_insert (chunk->const_table, lookup, lookup);
    }

  return lookup;
}

/* Strings.
 */
static gint
nearest_power (gint num)
{
  gint n = 1;

  while (n < num)
    n <<= 1;

  return n;
}

static gint
nearest_multiple (int num, const int block)
{
  gint n = block;

  while (n < num)
    n += block;

  return n;
}

static void
g_string_maybe_expand (GRealString* string, gint len)
{
  if (string->len + len >= string->alloc)
    {
      string->alloc = nearest_power (string->len + len + 1);
      string->str = g_realloc (string->str, string->alloc);
    }
}

static void
g_string_set_size (GRealString* string, gint size)
{
  if (string->alloc <= size) {
    string->alloc = nearest_power(size + 1);
    string->str = g_realloc (string->str, string->alloc);
  }
}

GString*
g_string_sized_new (guint dfl_size)
{
  GRealString *string;

  G_LOCK (string_mem_chunk);
  if (!string_mem_chunk)
    string_mem_chunk = g_mem_chunk_new ("string mem chunk",
					sizeof (GRealString),
					1024, G_ALLOC_AND_FREE);

  string = g_chunk_new (GRealString, string_mem_chunk);
  G_UNLOCK (string_mem_chunk);

  string->alloc = 0;
  string->len   = 0;
  string->str   = NULL;

  g_string_maybe_expand (string, MAX (dfl_size, 2));
  string->str[0] = 0;

  return (GString*) string;
}

GString*
g_string_new (const gchar *init)
{
  GString *string;

  string = g_string_sized_new (2);

  if (init)
    g_string_append (string, init);

  return string;
}

void
g_string_free (GString *string,
	       gint free_segment)
{
  g_return_if_fail (string != NULL);

  if (free_segment)
    g_free (string->str);

  G_LOCK (string_mem_chunk);
  g_mem_chunk_free (string_mem_chunk, string);
  G_UNLOCK (string_mem_chunk);
}

GString*
g_string_assign (GString *lval,
		 const gchar *rval)
{
  g_string_truncate (lval, 0);
  g_string_append (lval, rval);

  return lval;
}

GString*
g_string_truncate (GString* fstring,
		   gint len)
{
  GRealString *string = (GRealString*)fstring;

  g_return_val_if_fail (string != NULL, NULL);

  string->len = len;

  string->str[len] = 0;

  return fstring;
}

GString*
g_string_append (GString *fstring,
		 const gchar *val)
{
  GRealString *string = (GRealString*)fstring;
  int len;

  g_return_val_if_fail (string != NULL, NULL);
  g_return_val_if_fail (val != NULL, fstring);
  
  len = strlen (val);
  g_string_maybe_expand (string, len);

  strcpy (string->str + string->len, val);

  string->len += len;

  return fstring;
}

GString*
g_string_append_c (GString *fstring,
		   gchar c)
{
  GRealString *string = (GRealString*)fstring;

  g_return_val_if_fail (string != NULL, NULL);
  g_string_maybe_expand (string, 1);

  string->str[string->len++] = c;
  string->str[string->len] = 0;

  return fstring;
}

GString*
g_string_prepend (GString *fstring,
		  const gchar *val)
{
  GRealString *string = (GRealString*)fstring;
  gint len;

  g_return_val_if_fail (string != NULL, NULL);
  g_return_val_if_fail (val != NULL, fstring);

  len = strlen (val);
  g_string_maybe_expand (string, len);

  g_memmove (string->str + len, string->str, string->len);

  strncpy (string->str, val, len);

  string->len += len;

  string->str[string->len] = 0;

  return fstring;
}

GString*
g_string_prepend_c (GString *fstring,
		    gchar    c)
{
  GRealString *string = (GRealString*)fstring;

  g_return_val_if_fail (string != NULL, NULL);
  g_string_maybe_expand (string, 1);

  g_memmove (string->str + 1, string->str, string->len);

  string->str[0] = c;

  string->len += 1;

  string->str[string->len] = 0;

  return fstring;
}

GString*
g_string_insert (GString     *fstring,
		 gint         pos,
		 const gchar *val)
{
  GRealString *string = (GRealString*)fstring;
  gint len;

  g_return_val_if_fail (string != NULL, NULL);
  g_return_val_if_fail (val != NULL, fstring);
  g_return_val_if_fail (pos >= 0, fstring);
  g_return_val_if_fail (pos <= string->len, fstring);

  len = strlen (val);
  g_string_maybe_expand (string, len);

  g_memmove (string->str + pos + len, string->str + pos, string->len - pos);

  strncpy (string->str + pos, val, len);

  string->len += len;

  string->str[string->len] = 0;

  return fstring;
}

GString *
g_string_insert_c (GString *fstring,
		   gint     pos,
		   gchar    c)
{
  GRealString *string = (GRealString*)fstring;

  g_return_val_if_fail (string != NULL, NULL);
  g_return_val_if_fail (pos <= string->len, fstring);

  g_string_maybe_expand (string, 1);

  g_memmove (string->str + pos + 1, string->str + pos, string->len - pos);

  string->str[pos] = c;

  string->len += 1;

  string->str[string->len] = 0;

  return fstring;
}

GString*
g_string_erase (GString *fstring,
		gint pos,
		gint len)
{
  GRealString *string = (GRealString*)fstring;

  g_return_val_if_fail (string != NULL, NULL);
  g_return_val_if_fail (len >= 0, fstring);
  g_return_val_if_fail (pos >= 0, fstring);
  g_return_val_if_fail (pos <= string->len, fstring);
  g_return_val_if_fail (pos + len <= string->len, fstring);

  if (pos + len < string->len)
    g_memmove (string->str + pos, string->str + pos + len, string->len - (pos + len));

  string->len -= len;
  
  string->str[string->len] = 0;

  return fstring;
}

GString*
g_string_down (GString *fstring)
{
  GRealString *string = (GRealString*)fstring;
  gchar *s;

  g_return_val_if_fail (string != NULL, NULL);

  s = string->str;

  while (*s)
    {
      *s = tolower (*s);
      s++;
    }

  return fstring;
}

GString*
g_string_up (GString *fstring)
{
  GRealString *string = (GRealString*)fstring;
  gchar *s;

  g_return_val_if_fail (string != NULL, NULL);

  s = string->str;

  while (*s)
    {
      *s = toupper (*s);
      s++;
    }

  return fstring;
}

static void
g_string_sprintfa_int (GString     *string,
		       const gchar *fmt,
		       va_list      args)
{
  gchar *buffer;

  buffer = g_strdup_vprintf (fmt, args);
  g_string_append (string, buffer);
  g_free (buffer);
}

void
g_string_sprintf (GString *string,
		  const gchar *fmt,
		  ...)
{
  va_list args;

  g_string_truncate (string, 0);

  va_start (args, fmt);
  g_string_sprintfa_int (string, fmt, args);
  va_end (args);
}

void
g_string_sprintfa (GString *string,
		   const gchar *fmt,
		   ...)
{
  va_list args;

  va_start (args, fmt);
  g_string_sprintfa_int (string, fmt, args);
  va_end (args);
}

GStringError
g_string_readline (GString *dest_str,
		   gint     max_length,
		   gint     fd)
{
  gint count=0, retval;
  gchar c;

  g_return_val_if_fail (dest_str != NULL, G_STRING_ERROR_INVAL);
  g_return_val_if_fail (max_length > 0, G_STRING_ERROR_INVAL);
  g_string_truncate(dest_str, 0);

  for (count = 0; count < max_length; count++) {
    if ( (retval = read(fd, &c, 1)) == 1 ) {
      if (c == '\r') {
        continue;
      }
      if (c == '\n') {
        return(G_STRING_ERROR_NONE);
      }
      g_string_maybe_expand ((GRealString *) dest_str, 1);
      dest_str->str[dest_str->len++] = c;
      dest_str->str[dest_str->len] = 0;
    } else if (retval == 0) {
	return(G_STRING_ERROR_NODATA);
    } else {
      return(G_STRING_ERROR_READ);
    }
  }
  return(G_STRING_ERROR_LENGTH);
}

GStringError
g_string_readline_buffered (GString *dest_str,
			    GString *buff_str,
			    gint     max_length,
			    gint     fd,
			    gint     match_bare_cr)
{
  guint count, i=0, buff_size;

  g_return_val_if_fail (dest_str != NULL, G_STRING_ERROR_INVAL);
  g_return_val_if_fail (buff_str != NULL, G_STRING_ERROR_INVAL);
  g_return_val_if_fail (max_length > 0, G_STRING_ERROR_INVAL);

  /* Make the buffer a multiple of G_STRING_BLOCK_SIZE and
   * bigger then max_length */
  buff_size = nearest_multiple(max_length, G_STRING_BLOCK_SIZE);
  g_string_set_size( (GRealString *) buff_str, buff_size);

  do {
    /* Allow the buffer to empty before reading more data.
     * Prevents blocking on read() when data in the buffer */

    if (buff_str->len != 0) {
      /* Search for a CRLF, CR or LF */
      for (i = 0; i < max_length-1; i++) {

	/* Look for a CR */
	if (buff_str->str[i] == '\r') {

	  /* Check for CRLF */
	  if (buff_str->str[i+1] == '\n') {
	    buff_str->str[i] = '\0';
	    i++;
	  } else if (match_bare_cr) {
	    buff_str->str[i] = '\0';
	  } else {
	    continue;
	  }

	  /* Copy the line to the destination string and
	   * remove it from the buffer */
	  g_string_assign( dest_str, buff_str->str );
	  g_string_erase( buff_str, 0, i+1);
	  return (G_STRING_ERROR_NONE);
	}

	/* Look for LF */
	if (buff_str->str[i] == '\n') {
	  buff_str->str[i] = '\0';

	  /* Copy the line to the destination string and
	   * remove it from the buffer */
	  g_string_assign( dest_str, buff_str->str );
	  g_string_erase( buff_str, 0, i+1);
	  return (G_STRING_ERROR_NONE);      
	}

	/* If we hit a '\0' then we've exhausted the buffer */
	if (buff_str->str[i] == '\0') {
	  break;
	}
      }
    }

    /* Read in a block of data, appending it to the buffer */
    if ( (count = read(fd, buff_str->str + buff_str->len,
		       buff_size - buff_str->len - 1)) < 0) {
      return (G_STRING_ERROR_READ);
    } else if (count == 0) {
      return (G_STRING_ERROR_NODATA);
    } else {
      /* Fix up the buffer */
      buff_str->len += count;
      buff_str->str[buff_str->len] = '\0';
    }

  } while (i != max_length-1);

  /* If we get here then we have reached max_length */
  g_string_assign (dest_str, buff_str->str);
  g_string_truncate (dest_str, max_length-1);
  g_string_erase (buff_str, 0, max_length-1);

  return (G_STRING_ERROR_LENGTH);
}

GList*
g_string_tokenise (GString *string,
		   gchar   *delims,
		   gint     max_tokens,
		   gint     allow_empty)
{
  GList *tokens=NULL;
  GString *token;
  gchar *current, *start, c;
  guint count=1;

  g_return_val_if_fail (string != NULL, NULL);
  g_return_val_if_fail (delims != NULL, NULL);

  if (max_tokens < 1) {
    max_tokens = G_MAXINT;
  }

  current = string->str;
  while (*current) {
    /* Remove any leading delimiters */
    if (!allow_empty) {
      while ( *current && (strchr(delims, *current) != NULL) ) {
        current++;
      }
    }

    /* If we've reached max_tokens, use the remaining input string
     * as the last token */
    if (count == max_tokens) {
      token = g_string_new(current);
      tokens = g_list_append(tokens, token);
      return (tokens);
    }

    /* Find the extent of the current token */
    if ( *current ) {
      start = current;
      while ( *current && (strchr(delims, *current) == NULL) ) {
        current++;
      }
      c = *current;
      *current = '\0';
      token = g_string_new( start );
      *current = c;
      tokens = g_list_append(tokens, token);
      count++;
      if (*current) {
        current++;
      }
    }
  }

  return (tokens);
}

void
g_string_tokenise_free (GList *tokens,
			gint   free_token)
{

  if (free_token) {
    while(tokens) {
      g_string_free( (GString *) tokens->data, TRUE );
      tokens = g_list_next(tokens);
    }
  }

  g_list_free(tokens);
}