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/*
StarForth — Steady-State Virtual Machine Runtime
Copyright (c) 20232025 Robert A. James
All rights reserved.
This file is part of the StarForth project.
Licensed under the StarForth License, Version 1.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at:
https://github.com/star.4th@proton.me/StarForth/LICENSE.txt
This software is provided "AS IS", WITHOUT WARRANTY OF ANY KIND,
express or implied, including but not limited to the warranties of
merchantability, fitness for a particular purpose, and noninfringement.
See the License for the specific language governing permissions and
limitations under the License.
StarForth — Steady-State Virtual Machine Runtime
Copyright (c) 20232025 Robert A. James
All rights reserved.
This file is part of the StarForth project.
Licensed under the StarForth License, Version 1.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at:
https://github.com/star.4th@proton.me/StarForth/LICENSE.txt
This software is provided "AS IS", WITHOUT WARRANTY OF ANY KIND,
express or implied, including but not limited to the warranties of
merchantability, fitness for a particular purpose, and noninfringement.
See the License for the specific language governing permissions and
limitations under the License.
*/
// -----------------------------------------------------------------------------
// StarForth - Block I/O Factory (Implementation)
// -----------------------------------------------------------------------------
#include <stdint.h>
#include <stddef.h>
#include <string.h>
#include "blkio.h"
#include "blkio_factory.h"
/* Backends */
extern size_t blkio_file_state_size(void);
extern const blkio_vtable_t *blkio_file_vtable(void);
extern int blkio_file_init_state(void *state_mem, size_t state_len,
const char *path,
uint32_t total_blocks,
uint32_t fbs,
uint8_t read_only,
uint8_t create_if_missing,
uint8_t truncate_to_size,
void **out_opaque);
extern size_t blkio_ram_state_size(void);
extern const blkio_vtable_t *blkio_ram_vtable(void);
extern int blkio_ram_init_state(void *state_mem, size_t state_len,
uint8_t *base, uint32_t total_blocks,
uint32_t fbs, uint8_t read_only,
void **out_opaque);
/** @brief Return 1 if string @c s is non-NULL and non-empty. */
static int nonempty(const char *s) { return (s && *s); }
/**
* @brief Open a block I/O device using the best available backend.
*
* Selects the file backend when @c disk_img_path is non-empty, otherwise
* falls back to the RAM backend using @c ram_base / @c ram_blocks.
*
* File backend behaviour:
* - Creates the file if it does not exist (unless @c read_only is set).
* - Derives @c total_blocks from the file size when @c total_blocks == 0.
* - Sets @c *out_used_file = 1 on success.
*
* RAM backend behaviour:
* - @c ram_base must point to at least @c ram_blocks * @c fbs bytes of
* caller-owned memory that outlives the device.
*
* @param dev Output device handle to populate
* @param disk_img_path Path to disk image file, or NULL/empty for RAM
* @param read_only 1 = open read-only, 0 = read-write
* @param total_blocks Desired block count (0 = derive from file size)
* @param fbs FORTH block size in bytes (0 = use @c BLKIO_FORTH_BLOCK_SIZE)
* @param state_mem Caller-allocated state buffer (must be large enough)
* @param state_len Size of @c state_mem in bytes
* @param ram_base Base of RAM block array (used only when no disk path)
* @param ram_blocks Number of blocks in @c ram_base
* @param out_used_file Optional output: set to 1 if the file backend was used
* @return @c BLKIO_OK on success, or a @c BLKIO_E* error code
*/
int blkio_factory_open(blkio_dev_t *dev,
const char *disk_img_path,
uint8_t read_only,
uint32_t total_blocks,
uint32_t fbs,
void *state_mem,
size_t state_len,
uint8_t *ram_base,
uint32_t ram_blocks,
uint8_t *out_used_file) {
if (out_used_file) *out_used_file = 0;
if (!dev || !state_mem || state_len == 0) return BLKIO_EINVAL;
const uint32_t efbs = (fbs ? fbs : BLKIO_FORTH_BLOCK_SIZE);
if (nonempty(disk_img_path)) {
const size_t need = blkio_file_state_size();
if (state_len < need) return BLKIO_ENOSPACE;
void *opaque = NULL;
const uint8_t create_if_missing = read_only ? 0u : 1u;
const uint8_t truncate_to_size = (!read_only && total_blocks > 0) ? 1u : 0u;
int rc = blkio_file_init_state(state_mem, state_len,
disk_img_path,
total_blocks,
efbs,
read_only,
create_if_missing,
truncate_to_size,
&opaque);
if (rc != BLKIO_OK) return rc;
blkio_params_t p = {
.forth_block_size = efbs,
.total_blocks = total_blocks, /* 0 => derive in file_open */
.opaque = opaque
};
rc = blkio_open(dev, blkio_file_vtable(), &p);
if (rc == BLKIO_OK && out_used_file) *out_used_file = 1u;
return rc;
}
if (!ram_base || ram_blocks == 0) return BLKIO_EINVAL;
const size_t need_ram = blkio_ram_state_size();
if (state_len < need_ram) return BLKIO_ENOSPACE;
void *opaque = NULL;
int rc = blkio_ram_init_state(state_mem, state_len,
ram_base, ram_blocks,
efbs, read_only,
&opaque);
if (rc != BLKIO_OK) return rc;
const blkio_params_t p = {
.forth_block_size = efbs,
.total_blocks = ram_blocks,
.opaque = opaque
};
return blkio_open(dev, blkio_ram_vtable(), &p);
}