138 lines
4.6 KiB
C
138 lines
4.6 KiB
C
/*************************************************************************
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* *
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* YAP Prolog *
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* *
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* Yap Prolog was developed at NCCUP - Universidade do Porto *
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* *
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* Copyright L.Damas, V.S.Costa and Universidade do Porto 1985-1997 *
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* *
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**************************************************************************
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* *
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* File: VFS.h *
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* Last rev: 5/2/88 *
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* mods: *
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* comments: Virtual File System Access for YAP *
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* *
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*************************************************************************/
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#ifndef VFS_H
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#define VFS_H 1
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#include <string.h>
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#if HAVE_SYS_STAT_H
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#include <sys/stat.h>
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#endif
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#ifdef _WIN32
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#include <stdint.h>
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#ifndef uid_t
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#define uid_t int
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#endif
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#ifndef gid_t
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#define gid_t int
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#endif
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#endif
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typedef struct {
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dev_t st_dev; /* ID of device containing file */
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mode_t st_mode; /* Mode of file (see below) */
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uid_t st_uid; /* User ID of the file */
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gid_t st_gid; /* Group ID of the file */
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struct timespec st_atimespec; /* time of last access */
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struct timespec st_mtimespec; /* time of last data modification */
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struct timespec st_ctimespec; /* time of last status change */
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struct timespec st_birthtimespec; /* time of file creation(birth) */
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#if __ANDROID__
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off64_t st_size; /* file size, in bytes */
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#else
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off_t st_size; /* file size, in bytes */
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#endif
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} vfs_stat;
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typedef enum vfs_flags {
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VFS_CAN_WRITE = 0x1, /// we can write to files in this space
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VFS_CAN_EXEC = 0x2, /// we can execute files in this space
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VFS_CAN_SEEK = 0x4, /// we can seek within files in this space
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VFS_HAS_PREFIX = 0x8, /// has a prefix that identifies a file in this space
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VFS_HAS_SUFFIX = 0x10, /// has a suffix that describes the file.
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VFS_HAS_FUNCTION = 0x10, /// has a suffix that describes the file.
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} vfs_flags_t;
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typedef union {
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struct vfs *vfs;
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uintptr_t cell;
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size_t sz;
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void *pt;
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uintptr_t scalar;
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#if __ANDROID__
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AAssetManager *mgr;
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AAsset *asset;
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#endif
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} cell_size_t;
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typedef struct vfs {
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const char *name; /// A text that explains the file system
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uintptr_t vflags; /// the main flags describing the operation of the Fs.
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/// a way to identify a file in this VFS: two special cases, prefix and suffix
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const char *prefix;
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const char *suffix;
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bool (*id)(struct vfs *me, const char *s);
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/** operations */
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bool (*open)(struct vfs *me, struct stream_desc *st, const char *s,
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const char *io_mode);
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; /// open an object
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/// in this space, usual w,r,a,b flags plus B (store in a buffer)
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bool (*close)(struct stream_desc *stream); /// close the object
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int (*get_char)(struct stream_desc *stream); /// get an octet to the stream
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int (*putc)(int ch,
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struct stream_desc *stream); /// output an octet to the stream
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int64_t (*seek)(struct stream_desc *stream, int64_t offset,
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int whence); /// jump around the stream
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void *(*opendir)(struct vfs *me,
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const char *s); /// open a directory object, if one exists
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const char *(*nextdir)(
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void *d); /// walk to the next entry in a directory object
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void (*closedir)(void *d);
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; /// close access a directory object
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bool (*stat)(struct vfs *me, const char *s,
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vfs_stat *); /// obtain size, age, permissions of a file.
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bool (*isdir)(struct vfs *me, const char *s); /// verify whether is directory.
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bool (*exists)(struct vfs *me,
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const char *s); /// verify whether a file exists.
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bool (*chdir)(struct vfs *me,
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const char *s); /// set working directory (may be virtual).
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encoding_t enc; /// how the file is encoded.
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YAP_Term (*parsers)(void *stream); // a set of parsers that can read the
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// stream and generate a YAP_Term
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int (*writers)(int ch, void *stream);
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; /// convert a YAP_Term into this space
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const char *virtual_cwd;
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/** VFS dep
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endent area */
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cell_size_t priv[4];
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struct vfs *next;
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} VFS_t;
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extern VFS_t *GLOBAL_VFS;
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static inline VFS_t *vfs_owner(const char *fname) {
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return NULL;
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VFS_t *me = GLOBAL_VFS;
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int d;
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size_t sz0 = strlen(fname);
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while (me) {
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if (me->vflags & VFS_HAS_PREFIX && strstr(fname, me->prefix))
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return me;
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size_t sz = strlen(me->suffix);
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if (me->vflags & VFS_HAS_SUFFIX && (d = (sz0 - sz)) >= 0 &&
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strcmp(fname + d, me->suffix) == 0)
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return me;
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if (me->vflags & VFS_HAS_FUNCTION && (me->id(me, fname))) {
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return me;
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}
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me = me->next;
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}
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return NULL;
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}
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#endif
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