first revision

libblock/Makefile

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+#
+#  (c) 2005 Laurent Vivier <LaurentVivier@wanadoo.fr>
+#
+
+TOP=$(shell pwd)
+
+CFLAGS	= -nostdlib -nodefaultlibs -Wall -Werror -Wno-multichar -fpic -O2
+CPPFLAGS = -I$(TOP)/../libmacos -DARCH_M68K -I$(TOP)/../libstream
+
+LIBRARY = libblock.a
+
+SOURCES = block_close.c block_fstat.c block_lseek.c block_open.c block_read.c
+
+HEADERS = libblock.h
+
+all: $(LIBRARY)
+
+include $(TOP)/../Rules.mk

libblock/block_close.c

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+/*
+ *
+ * (c) 2005 Laurent Vivier <LaurentVivier@wanadoo.fr>
+ *
+ */
+
+#include <stdlib.h>
+
+#include "libblock.h"
+
+int block_close(block_FILE *file)
+{
+	if (file == NULL)
+		return -1;
+
+	free(file);
+
+	return 0;
+}

libblock/block_fstat.c

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+/*
+ *
+ * (c) 2005 Laurent Vivier <LaurentVivier@wanadoo.fr>
+ *
+ */
+
+#include "libblock.h"
+
+int block_fstat(block_FILE *file, struct stream_stat *buf)
+{
+	if (buf == NULL)
+		return -1;
+	if (file->size == -1)
+		return -1;
+
+	buf->st_size = file->size;
+
+	return 0;
+}

libblock/block_lseek.c

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+/*
+ *
+ * (c) 2005 Laurent Vivier <LaurentVivier@wanadoo.fr>
+ *
+ */
+
+#include "libblock.h"
+
+int block_lseek(block_FILE *file, off_t offset, int whence)
+{
+	long new_offset;
+
+	switch(whence)
+	{
+	case SEEK_SET:
+		new_offset = offset;
+		break;
+	case SEEK_CUR:
+		new_offset = file->offset + offset;
+		break;
+	default:
+		return -1;
+	}
+
+	if (new_offset < 0)
+		return -1;
+
+	file->offset = new_offset;
+
+	return new_offset;
+}

libblock/block_open.c

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+/*
+ *
+ * (c) 2005 Laurent Vivier <LaurentVivier@wanadoo.fr>
+ *
+ */
+
+#include <stdlib.h>
+
+#include "libblock.h"
+
+#define NB_SECTORS	(18*2)
+
+/*
+ * path is "<first>,<size>"
+ * where <first> is the offset of the first byte to read on the device
+ * and <size> is the number of bytes to read then.
+ */
+
+block_FILE *block_open(device_io_t *device, char *path)
+{
+	block_FILE *block;
+	int blocksize = device->get_blocksize(device);
+	int first, size;
+
+	first = strtol(path, &path, 0);
+
+	if ( (*path != ',') && (*path != 0) )
+		return NULL;
+
+	if (*path == ',')
+	{
+		size = strtol(path, &path, 0);
+		if (*path != 0)
+			return NULL;
+	}
+	else
+		size = -1;
+	
+	block = (block_FILE *)malloc(sizeof(block_FILE) + 
+				     NB_SECTORS * blocksize);
+	if (block == NULL)
+		return NULL;
+
+	block->base = first;
+	block->offset = 0;
+	block->size = size;
+	block->device = device;
+	block->current = -1;
+	block->buffer_size = NB_SECTORS * blocksize;
+
+	return block;
+}

libblock/block_read.c

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+/*
+ *
+ * (c) 2005 Laurent Vivier <LaurentVivier@wanadoo.fr>
+ *
+ */
+
+#include <string.h>
+
+#include "libblock.h"
+
+size_t block_read(block_FILE *file, void *ptr, size_t size)
+{
+	int read = 0;
+	int ret;
+	int blocksize = file->device->get_blocksize(&file->device);
+
+	while (size != 0)
+	{
+		int part;
+		int block_nb = (file->offset + file->base) / file->buffer_size;
+		int block_offset = (file->offset + file->base) % file->buffer_size;
+
+		if (block_nb != file->current)
+		{
+			ret = file->device->read_sector(file->device,
+					(block_nb * file->buffer_size) / blocksize,
+						 file->buffer, 
+						 file->buffer_size);
+			if (ret == -1)
+				return read;
+			file->current = block_nb;
+		}
+
+		part = file->buffer_size - block_offset;
+		if (part > size)
+			part = size;
+		memcpy(ptr, file->buffer + block_offset, part);
+
+		size -= part;
+		ptr = (char*)ptr + part;
+		file->offset += part;
+		read += part;
+	}
+
+	return read;
+}

libblock/libblock.h

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+/*
+ *
+ * (c) 2005 Laurent Vivier <LaurentVivier@wanadoo.fr>
+ *
+ */
+
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <libstream.h>
+
+typedef struct {
+	int base;
+	int offset;
+	int size;
+	device_io_t *device;
+	int current;
+	int buffer_size;
+	unsigned char buffer[0];
+} block_FILE;
+
+extern block_FILE *block_open(device_io_t *device, char *path);
+extern int block_close(block_FILE *file);
+extern size_t block_read(block_FILE *file, void *ptr, size_t size);
+extern int block_lseek(block_FILE *file, off_t offset, int whence);
+extern int block_fstat(block_FILE *file, struct stream_stat *buf);