Import of pdisk from apple, BSD licensed code. Archive dated Feb 18 1998

This is a HFS partition editing tool.

1 files changed, 334 insertions, 0 deletions

diff --git a/sbin/pdisk/deblock_media.c b/sbin/pdisk/deblock_media.c
new file mode 100644
index 00000000000..cb752d70554
--- /dev/null
+++ b/sbin/pdisk/deblock_media.c
@@ -0,0 +1,334 @@
+/*
+ * deblock_media.c -
+ *
+ * Written by Eryk Vershen (eryk@apple.com)
+ */
+
+/*
+ * Copyright 1997,1998 by Apple Computer, Inc.
+ *              All Rights Reserved 
+ *  
+ * Permission to use, copy, modify, and distribute this software and 
+ * its documentation for any purpose and without fee is hereby granted, 
+ * provided that the above copyright notice appears in all copies and 
+ * that both the copyright notice and this permission notice appear in 
+ * supporting documentation. 
+ *  
+ * APPLE COMPUTER DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE 
+ * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 
+ * FOR A PARTICULAR PURPOSE. 
+ *  
+ * IN NO EVENT SHALL APPLE COMPUTER BE LIABLE FOR ANY SPECIAL, INDIRECT, OR 
+ * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM 
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN ACTION OF CONTRACT, 
+ * NEGLIGENCE, OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION 
+ * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 
+ */
+
+
+// for malloc() & free()
+#include <stdlib.h>
+// for memcpy()
+#include <string.h>
+
+#include "deblock_media.h"
+
+
+/*
+ * Defines
+ */
+
+
+/*
+ * Types
+ */
+typedef struct deblock_media *DEBLOCK_MEDIA;
+
+struct deblock_media {
+    struct media    m;
+    long            need_filtering;
+    MEDIA           next_media;
+    unsigned long   next_block_size;
+    unsigned char   *buffer;
+};
+
+struct deblock_globals {
+    long        exists;
+    long        kind;
+};
+
+
+/*
+ * Global Constants
+ */
+
+
+/*
+ * Global Variables
+ */
+static long deblock_inited = 0;
+static struct deblock_globals deblock_info;
+
+/*
+ * Forward declarations
+ */
+void deblock_init(void);
+DEBLOCK_MEDIA new_deblock_media(void);
+long read_deblock_media(MEDIA m, long long offset, unsigned long count, void *address);
+long write_deblock_media(MEDIA m, long long offset, unsigned long count, void *address);
+long close_deblock_media(MEDIA m);
+long os_reload_deblock_media(MEDIA m);
+
+
+/*
+ * Routines
+ */
+void
+deblock_init(void)
+{
+    if (deblock_inited != 0) {
+	return;
+    }
+    deblock_inited = 1;
+    
+    deblock_info.kind = allocate_media_kind();
+}
+
+
+DEBLOCK_MEDIA
+new_deblock_media(void)
+{
+    return (DEBLOCK_MEDIA) new_media(sizeof(struct deblock_media));
+}
+
+
+MEDIA
+open_deblock_media(long new_block_size, MEDIA m)
+{
+    DEBLOCK_MEDIA   a;
+    unsigned long   block_size;
+    
+    if (deblock_inited == 0) {
+	deblock_init();
+    }
+    
+    a = 0;
+    if (m != 0) {
+	block_size = media_granularity(m);
+
+	if (new_block_size == block_size) {
+	    return m;
+
+	} else if (new_block_size > block_size) {
+	    if ((new_block_size % block_size) == 0) {
+		/* no filtering necessary */
+		a = new_deblock_media();
+		if (a != 0) {
+		    a->need_filtering = 0;
+		    a->next_block_size = block_size;
+		    a->buffer = 0;
+		}
+	    } else {
+		/* too hard to bother with */
+	    }
+	} else /* new_block_size < block_size */ {
+	    if ((block_size % new_block_size) == 0) {
+		/* block & unblock */
+		a = new_deblock_media();
+		if (a != 0) {
+		    a->need_filtering = 1;
+		    a->next_block_size = block_size;
+		    a->buffer = malloc(block_size);
+		}
+	    } else {
+		/* too hard to bother with */
+	    }
+	}
+	if (a != 0) {
+	    a->m.kind = deblock_info.kind;
+	    a->m.grain = new_block_size;
+	    a->m.size_in_bytes = media_total_size(m);
+	    a->m.do_read = read_deblock_media;
+	    a->m.do_write = write_deblock_media;
+	    a->m.do_close = close_deblock_media;
+	    a->m.do_os_reload = os_reload_deblock_media;
+	    a->next_media = m;
+	}
+    }
+    return (MEDIA) a;
+}
+
+
+long
+read_deblock_media(MEDIA m, long long offset, unsigned long count, void *address)
+{
+    DEBLOCK_MEDIA a;
+    long rtn_value;
+    unsigned long next_size;
+    unsigned long partial_offset;
+    unsigned long partial_count;
+    long long cur_offset;
+    unsigned long remainder;
+    unsigned char *addr;
+
+    a = (DEBLOCK_MEDIA) m;
+    rtn_value = 0;
+    if (a == 0) {
+	/* no media */
+    } else if (a->m.kind != deblock_info.kind) {
+	/* wrong kind - XXX need to error here - this is an internal problem */
+    } else if (count <= 0 || count % a->m.grain != 0) {
+	/* can't handle size */
+    } else if (offset < 0 || offset % a->m.grain != 0) {
+	/* can't handle offset */
+    } else if (a->need_filtering == 0) {
+	rtn_value = read_media(a->next_media, offset, count, address);
+    } else {
+	next_size = a->next_block_size;
+	addr = address;
+	cur_offset = offset;
+	remainder = count;
+	rtn_value = 1;
+
+	/* read partial */
+	partial_offset = cur_offset % next_size;
+	if (partial_offset != 0) {
+	    partial_count = next_size - partial_offset;
+	    if (partial_count > remainder) {
+		partial_count = remainder;
+	    }
+	    rtn_value = read_media(a->next_media, cur_offset - partial_offset, next_size, a->buffer);
+	    if (rtn_value != 0) {
+		memcpy (addr, a->buffer + partial_offset, partial_count);
+		addr += partial_count;
+		cur_offset += partial_count;
+		remainder -= partial_count;
+	    }
+	}
+	/* read fulls as long as needed */
+	if (rtn_value != 0 && remainder > next_size) {
+	    partial_count = remainder - (remainder % next_size);
+	    rtn_value = read_media(a->next_media, cur_offset, partial_count, addr);
+	    addr += partial_count;
+	    cur_offset += partial_count;
+	    remainder -= partial_count;
+	}
+	/* read partial */
+	if (rtn_value != 0 && remainder > 0) {
+	    partial_count = remainder;
+	    rtn_value = read_media(a->next_media, cur_offset, next_size, a->buffer);
+	    if (rtn_value != 0) {
+		memcpy (addr, a->buffer, partial_count);
+	    }
+	}
+    }
+    return rtn_value;
+}
+
+
+long
+write_deblock_media(MEDIA m, long long offset, unsigned long count, void *address)
+{
+    DEBLOCK_MEDIA a;
+    long rtn_value;
+    unsigned long next_size;
+    unsigned long partial_offset;
+    unsigned long partial_count;
+    long long cur_offset;
+    unsigned long remainder;
+    unsigned char *addr;
+    
+    a = (DEBLOCK_MEDIA) m;
+    rtn_value = 0;
+    if (a == 0) {
+	/* no media */
+    } else if (a->m.kind != deblock_info.kind) {
+	/* wrong kind - XXX need to error here - this is an internal problem */
+    } else if (count <= 0 || count % a->m.grain != 0) {
+	/* can't handle size */
+    } else if (offset < 0 || offset % a->m.grain != 0) {
+	/* can't handle offset */
+    } else if (a->need_filtering == 0) {
+	rtn_value = write_media(a->next_media, offset, count, address);
+    } else {
+	next_size = a->next_block_size;
+	addr = address;
+	cur_offset = offset;
+	remainder = count;
+	rtn_value = 1;
+
+	/* write partial */
+	partial_offset = cur_offset % next_size;
+	if (partial_offset != 0) {
+	    partial_count = next_size - partial_offset;
+	    if (partial_count > remainder) {
+		partial_count = remainder;
+	    }
+	    rtn_value = read_media(a->next_media, cur_offset - partial_offset, next_size, a->buffer);
+	    if (rtn_value != 0) {
+		memcpy (a->buffer + partial_offset, addr, partial_count);
+		rtn_value = write_media(a->next_media, cur_offset - partial_offset, next_size, a->buffer);
+		addr += partial_count;
+		cur_offset += partial_count;
+		remainder -= partial_count;
+	    }
+	}
+	/* write fulls as long as needed */
+	if (rtn_value != 0 && remainder > next_size) {
+	    partial_count = remainder - (remainder % next_size);
+	    rtn_value = write_media(a->next_media, cur_offset, partial_count, addr);
+	    addr += partial_count;
+	    cur_offset += partial_count;
+	    remainder -= partial_count;
+	}
+	/* write partial */
+	if (rtn_value != 0 && remainder > 0) {
+	    partial_count = remainder;
+	    rtn_value = read_media(a->next_media, cur_offset, next_size, a->buffer);
+	    if (rtn_value != 0) {
+		memcpy (a->buffer, addr, partial_count);
+		rtn_value = write_media(a->next_media, cur_offset, next_size, a->buffer);
+	    }
+	}
+    }
+    /* recompute size to handle file media */
+    a->m.size_in_bytes = media_total_size(a->next_media);
+    return rtn_value;
+}
+
+
+long
+close_deblock_media(MEDIA m)
+{
+    DEBLOCK_MEDIA a;
+    
+    a = (DEBLOCK_MEDIA) m;
+    if (a == 0) {
+	return 0;
+    } else if (a->m.kind != deblock_info.kind) {
+	/* XXX need to error here - this is an internal problem */
+	return 0;
+    }
+    
+    close_media(a->next_media);
+    free(a->buffer);
+    return 1;
+}
+
+
+long
+os_reload_deblock_media(MEDIA m)
+{
+    DEBLOCK_MEDIA a;
+    
+    a = (DEBLOCK_MEDIA) m;
+    if (a == 0) {
+	return 0;
+    } else if (a->m.kind != deblock_info.kind) {
+	/* XXX need to error here - this is an internal problem */
+	return 0;
+    }
+    
+    os_reload_media(a->next_media);
+    return 1;
+}