| /* |
| * Copyright (C) 2010 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #include <assert.h> |
| #include <errno.h> |
| #include <stdint.h> |
| #include <stdlib.h> |
| #include <string.h> |
| |
| #include "backed_block.h" |
| |
| struct backed_block { |
| unsigned int block; |
| unsigned int len; |
| enum backed_block_type type; |
| union { |
| struct { |
| void *data; |
| } data; |
| struct { |
| char *filename; |
| int64_t offset; |
| } file; |
| struct { |
| uint32_t val; |
| } fill; |
| }; |
| struct backed_block *next; |
| }; |
| |
| struct backed_block_list { |
| struct backed_block *data_blocks; |
| struct backed_block *last_used; |
| }; |
| |
| struct backed_block *backed_block_iter_new(struct backed_block_list *bbl) |
| { |
| return bbl->data_blocks; |
| } |
| |
| struct backed_block *backed_block_iter_next(struct backed_block *bb) |
| { |
| return bb->next; |
| } |
| |
| unsigned int backed_block_len(struct backed_block *bb) |
| { |
| return bb->len; |
| } |
| |
| unsigned int backed_block_block(struct backed_block *bb) |
| { |
| return bb->block; |
| } |
| |
| void *backed_block_data(struct backed_block *bb) |
| { |
| assert(bb->type == BACKED_BLOCK_DATA); |
| return bb->data.data; |
| } |
| |
| const char *backed_block_filename(struct backed_block *bb) |
| { |
| assert(bb->type == BACKED_BLOCK_FILE); |
| return bb->file.filename; |
| } |
| |
| int64_t backed_block_file_offset(struct backed_block *bb) |
| { |
| assert(bb->type == BACKED_BLOCK_FILE); |
| return bb->file.offset; |
| } |
| |
| uint32_t backed_block_fill_val(struct backed_block *bb) |
| { |
| assert(bb->type == BACKED_BLOCK_FILL); |
| return bb->fill.val; |
| } |
| |
| enum backed_block_type backed_block_type(struct backed_block *bb) |
| { |
| return bb->type; |
| } |
| |
| struct backed_block_list *backed_block_list_new(void) |
| { |
| struct backed_block_list *b = calloc(sizeof(struct backed_block_list), 1); |
| |
| return b; |
| } |
| |
| void backed_block_list_destroy(struct backed_block_list *bbl) |
| { |
| if (bbl->data_blocks) { |
| struct backed_block *bb = bbl->data_blocks; |
| while (bb) { |
| struct backed_block *next = bb->next; |
| if (bb->type == BACKED_BLOCK_FILE) { |
| free(bb->file.filename); |
| } |
| |
| free(bb); |
| bb = next; |
| } |
| } |
| |
| free(bbl); |
| } |
| |
| static int queue_bb(struct backed_block_list *bbl, struct backed_block *new_bb) |
| { |
| struct backed_block *bb; |
| |
| if (bbl->data_blocks == NULL) { |
| bbl->data_blocks = new_bb; |
| return 0; |
| } |
| |
| if (bbl->data_blocks->block > new_bb->block) { |
| new_bb->next = bbl->data_blocks; |
| bbl->data_blocks = new_bb; |
| return 0; |
| } |
| |
| /* Optimization: blocks are mostly queued in sequence, so save the |
| pointer to the last bb that was added, and start searching from |
| there if the next block number is higher */ |
| if (bbl->last_used && new_bb->block > bbl->last_used->block) |
| bb = bbl->last_used; |
| else |
| bb = bbl->data_blocks; |
| bbl->last_used = new_bb; |
| |
| for (; bb->next && bb->next->block < new_bb->block; bb = bb->next) |
| ; |
| |
| if (bb->next == NULL) { |
| bb->next = new_bb; |
| } else { |
| new_bb->next = bb->next; |
| bb->next = new_bb; |
| } |
| |
| return 0; |
| } |
| |
| /* Queues a fill block of memory to be written to the specified data blocks */ |
| int backed_block_add_fill(struct backed_block_list *bbl, unsigned int fill_val, |
| unsigned int len, unsigned int block) |
| { |
| struct backed_block *bb = calloc(1, sizeof(struct backed_block)); |
| if (bb == NULL) { |
| return -ENOMEM; |
| } |
| |
| bb->block = block; |
| bb->len = len; |
| bb->type = BACKED_BLOCK_FILL; |
| bb->fill.val = fill_val; |
| bb->next = NULL; |
| |
| return queue_bb(bbl, bb); |
| } |
| |
| /* Queues a block of memory to be written to the specified data blocks */ |
| int backed_block_add_data(struct backed_block_list *bbl, void *data, |
| unsigned int len, unsigned int block) |
| { |
| struct backed_block *bb = calloc(1, sizeof(struct backed_block)); |
| if (bb == NULL) { |
| return -ENOMEM; |
| } |
| |
| bb->block = block; |
| bb->len = len; |
| bb->type = BACKED_BLOCK_DATA; |
| bb->data.data = data; |
| bb->next = NULL; |
| |
| return queue_bb(bbl, bb); |
| } |
| |
| /* Queues a chunk of a file on disk to be written to the specified data blocks */ |
| int backed_block_add_file(struct backed_block_list *bbl, const char *filename, |
| int64_t offset, unsigned int len, unsigned int block) |
| { |
| struct backed_block *bb = calloc(1, sizeof(struct backed_block)); |
| if (bb == NULL) { |
| return -ENOMEM; |
| } |
| |
| bb->block = block; |
| bb->len = len; |
| bb->type = BACKED_BLOCK_FILE; |
| bb->file.filename = strdup(filename); |
| bb->file.offset = offset; |
| bb->next = NULL; |
| |
| return queue_bb(bbl, bb); |
| } |