src/data/file-handle-def.h

   1 /* PSPP - a program for statistical analysis.
   2    Copyright (C) 1997-9, 2000, 2005, 2006, 2010, 2011, 2013 Free Software Foundation, Inc.
   3
   4    This program is free software: you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation, either version 3 of the License, or
   7    (at your option) any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program.  If not, see <http://www.gnu.org/licenses/>. */
  16
  17 #ifndef FILE_HANDLE_DEF_H
  18 #define FILE_HANDLE_DEF_H
  19
  20 #include "libpspp/compiler.h"
  21 #include <stdbool.h>
  22 #include <stddef.h>
  23
  24 struct dataset;
  25
  26 /* What a file handle refers to.
  27    (Ordinarily only a single value is allowed, but fh_open()
  28    and fh_parse() take a mask.) */
  29 enum fh_referent
  30   {
  31     FH_REF_FILE = 001,          /* Ordinary file (the most common case). */
  32     FH_REF_INLINE = 002,        /* The inline file. */
  33     FH_REF_DATASET = 004        /* Dataset. */
  34   };
  35
  36 /* File modes. */
  37 enum fh_mode
  38   {
  39     FH_MODE_TEXT,               /* New-line delimited lines. */
  40     FH_MODE_FIXED,              /* Fixed-length records. */
  41     FH_MODE_VARIABLE,           /* Binary variable-length records. */
  42     FH_MODE_360_VARIABLE,       /* IBM 360 variable-length records. */
  43     FH_MODE_360_SPANNED,        /* IBM 360 variable-length, spanned records. */
  44   };
  45
  46 /* Ways to access a file. */
  47 enum fh_access
  48   {
  49     FH_ACC_READ,                /* Read from it. */
  50     FH_ACC_WRITE                /* Write to it. */
  51   };
  52
  53 /* How a line ends.
  54
  55    This affects only writing FH_MODE_TEXT files.  Writing in other modes does
  56    not use line ends, and reading in FH_MODE_TEXT mode accepts all forms of
  57    line ends. */
  58 enum fh_line_ends
  59   {
  60     FH_END_LF,                  /* Unix line ends (\n). */
  61     FH_END_CRLF                 /* MS-DOS line ends (\r\n). */
  62   };
  63
  64 /* Properties of a file handle. */
  65 struct fh_properties
  66   {
  67     enum fh_mode mode;          /* File mode. */
  68     enum fh_line_ends line_ends; /* Line ends for text files. */
  69     size_t record_width;        /* Length of fixed-format records. */
  70     size_t tab_width;           /* Tab width, 0=do not expand tabs. */
  71     const char *encoding;       /* Charset for contents. */
  72   };
  73
  74 void fh_init (void);
  75 void fh_done (void);
  76
  77 /* Creating file handles. */
  78 struct file_handle *fh_create_file (const char *handle_name,
  79                                     const char *file_name, const char *file_name_encoding,
  80                                     const struct fh_properties *);
  81 struct file_handle *fh_create_dataset (struct dataset *);
  82 const struct fh_properties *fh_default_properties (void);
  83
  84 /* Reference management. */
  85 struct file_handle *fh_ref (struct file_handle *) WARN_UNUSED_RESULT;
  86 void fh_unref (struct file_handle *);
  87 void fh_unname (struct file_handle *);
  88
  89 /* Finding file handles. */
  90 struct file_handle *fh_from_id (const char *handle_name);
  91 struct file_handle *fh_inline_file (void);
  92
  93 /* Generic properties of file handles. */
  94 const char *fh_get_id (const struct file_handle *);
  95 const char *fh_get_name (const struct file_handle *);
  96 enum fh_referent fh_get_referent (const struct file_handle *);
  97 const char *fh_get_encoding (const struct file_handle *);
  98
  99 bool fh_equal (const struct file_handle *, const struct file_handle *);
 100
 101 /* Properties of FH_REF_FILE file handles. */
 102 const char *fh_get_file_name (const struct file_handle *);
 103 const char *fh_get_file_name_encoding (const struct file_handle *handle);
 104 enum fh_mode fh_get_mode (const struct file_handle *) ;
 105 enum fh_line_ends fh_get_line_ends (const struct file_handle *);
 106
 107 /* Properties of FH_REF_FILE and FH_REF_INLINE file handles. */
 108 size_t fh_get_record_width (const struct file_handle *);
 109 size_t fh_get_tab_width (const struct file_handle *);
 110
 111 /* Properties of FH_REF_DATASET file handles. */
 112 struct dataset *fh_get_dataset (const struct file_handle *);
 113
 114 /* Mutual exclusion for access . */
 115 struct fh_lock *fh_lock (struct file_handle *, enum fh_referent mask,
 116                          const char *type, enum fh_access, bool exclusive);
 117 bool fh_unlock (struct fh_lock *);
 118 void *fh_lock_get_aux (const struct fh_lock *);
 119 void fh_lock_set_aux (struct fh_lock *, void *aux);
 120 bool fh_is_locked (const struct file_handle *, enum fh_access);
 121
 122 /* Default file handle for DATA LIST, REREAD, REPEATING DATA
 123    commands. */
 124 struct file_handle *fh_get_default_handle (void);
 125 void fh_set_default_handle (struct file_handle *);
 126
 127 #endif