diff options
Diffstat (limited to 'nerv/lib/io/chunk_file.c')
| -rw-r--r-- | nerv/lib/io/chunk_file.c | 239 |
1 files changed, 239 insertions, 0 deletions
diff --git a/nerv/lib/io/chunk_file.c b/nerv/lib/io/chunk_file.c new file mode 100644 index 0000000..a305962 --- /dev/null +++ b/nerv/lib/io/chunk_file.c @@ -0,0 +1,239 @@ +#include "../../common.h" +#include "chunk_file.h" +#include <stdlib.h> +#include <string.h> +#define PARAM_HEADER_SIZE 16 + +static size_t read_chunk_header_plain(FILE *fp, int *status) { + static char buff[PARAM_HEADER_SIZE]; + int i; + size_t size = 0; + if (fread(buff, 1, PARAM_HEADER_SIZE, fp) != PARAM_HEADER_SIZE) + { + if (feof(fp)) *status = CF_END_OF_FILE; + else + { + *status = CF_INVALID_FORMAT; + return 0; + } + } + else *status = CF_NORMAL; + for (i = 0; i < PARAM_HEADER_SIZE; i++) + if (isdigit(buff[i])) + size = size * 10 + buff[i] - '0'; +/* fprintf(stderr, "header: %lu\n", size); */ + return size; +} + +static void write_chunk_header_plain(FILE *fp, size_t size, int *status) { + static char buff[PARAM_HEADER_SIZE]; + int i; + for (i = PARAM_HEADER_SIZE - 3; i > 0; i--, size /= 10) + buff[i] = size % 10 + '0'; + if (size) + { + *status = CF_SECTION_OVERFLOW; + return; + } + buff[0] = '['; + buff[PARAM_HEADER_SIZE - 2] = ']'; + buff[PARAM_HEADER_SIZE - 1] = '\n'; + if (fwrite(buff, 1, PARAM_HEADER_SIZE, fp) != PARAM_HEADER_SIZE) + { + *status = CF_WRITE_ERROR; + return; + } + *status = CF_NORMAL; +} + +static ChunkData *get_chunk_data(FILE *fp, ChunkInfo *info) { + ChunkData *cdp = (ChunkData *)malloc(sizeof(ChunkData)); + cdp->data = (char *)malloc(info->length); + cdp->fp = fmemopen(cdp->data, info->length, "r"); + assert(fseeko(fp, info->offset, SEEK_SET) == 0); + if (fread(cdp->data, 1, info->length, fp) != (size_t)info->length) + return NULL; + return cdp; +} + +static const char *read_chunk_metadata(FILE *fp, const char *fn, int *status) { +#define LINEBUFF_SIZE 1024 +#define LUA_RETURN "return " +#define LUA_RETURN_LEN (sizeof(LUA_RETURN) - 1) + static char buff[LUA_RETURN_LEN + LINEBUFF_SIZE] = LUA_RETURN; + *status = fgets(buff + LUA_RETURN_LEN, + LINEBUFF_SIZE, fp) == (buff + LUA_RETURN_LEN) ? \ + CF_NORMAL : CF_INVALID_FORMAT; + fprintf(stderr, "metadata: %s\n", buff); + return buff; +} + +static void write_chunk_metadata(FILE *fp, const char *mdstr, int *status) { + size_t size = strlen(mdstr); + if (fwrite(mdstr, 1, size, fp) != size || + fprintf(fp, "\n") < 0) + { + *status = CF_WRITE_ERROR; + return; + } + /* fprintf(stderr, "metadata: %s\n", metadata_str); */ + *status = CF_NORMAL; +} + +static ChunkFile *open_write(const char *fn, int *status) { + ChunkFile *cfp; + FILE *fp = fopen(fn, "w"); + + if (!fp) + { + *status = CF_ERR_OPEN_FILE; + return NULL; + } + cfp = (ChunkFile *)malloc(sizeof(ChunkFile)); + cfp->fp = fp; + cfp->status = CF_WRITE; + *status = CF_NORMAL; + return cfp; +} + +static ChunkFile *open_read(const char *fn, int *status) { + size_t chunk_len; + off_t offset; + int i; + const char *mdstr; + ChunkFile *cfp; + ChunkInfo *head = NULL; + FILE *fp = fopen(fn, "r"); + + if (!fp) + { + *status = CF_ERR_OPEN_FILE; + return NULL; + } + cfp = (ChunkFile *)malloc(sizeof(ChunkFile)); + cfp->fp = fp; + cfp->status = CF_READ; + offset = ftello(fp); + /* fprintf(stderr, "%d\n", (int)offset); */ + for (i = 0;; offset += chunk_len, i++) + { + ChunkInfo *cip; + fprintf(stderr, "reading chunk %d from %d\n", i, (int)offset); + /* skip to the begining of chunk i */ + if (fseeko(fp, offset, SEEK_SET) != 0) + { + *status = CF_INVALID_FORMAT; + return NULL; + } + /* read header */ + chunk_len = read_chunk_header_plain(fp, status); + if (*status == CF_END_OF_FILE) break; + if (*status != CF_NORMAL) + return NULL; + cip = (ChunkInfo *)malloc(sizeof(ChunkInfo)); + /* read metadata */ + mdstr = read_chunk_metadata(fp, fn, status); + if (*status != CF_NORMAL) + return NULL; + cip->metadata = strdup(mdstr); + cip->offset = ftello(fp); + cip->length = chunk_len - (cip->offset - offset); + /* fprintf(stderr, "%d + %d (skip %lu)\n", (int)cip->offset, + (int)cip->length, chunk_len); */ + cip->next = head; + head = cip; + } + *status = CF_NORMAL; + cfp->info = head; + return cfp; +} + +ChunkFile *nerv_chunk_file_create(const char *fn, const char *mode, int *status) { + int rd = 1, bin = 0; + size_t i, len = strlen(mode); + for (i = 0; i < len; i++) + switch (mode[i]) + { + case 'r': rd = 1; break; + case 'w': rd = 0; break; + case 'b': bin = 1; break; + } + return rd ? open_read(fn, status) : \ + open_write(fn, status); +} + +int nerv_chunk_file_write_chunkdata(ChunkFile *cfp, const char *mdstr, + ChunkDataWriter_t writer, void *writer_arg) { + int status; + off_t start; + size_t size; + if (cfp->status != CF_WRITE) + return CF_INVALID_OP; + start = ftello(cfp->fp); + write_chunk_header_plain(cfp->fp, 0, &status); /* fill zeros */ + if (status != CF_NORMAL) return status; + write_chunk_metadata(cfp->fp, mdstr, &status); + if (status != CF_NORMAL) return status; + writer(writer_arg); + size = ftello(cfp->fp) - start; + fseeko(cfp->fp, start, SEEK_SET); + /* write the calced size */ + write_chunk_header_plain(cfp->fp, size, &status); + if (status != CF_NORMAL) return status; + fseeko(cfp->fp, 0, SEEK_END); + return CF_NORMAL; +} + +ChunkData *nerv_chunk_file_get_chunkdata(ChunkFile *cfp, ChunkInfo *cip, int *status) { + ChunkData *cdp; + if (cfp->status != CF_READ) + { + *status = CF_INVALID_OP; + return NULL; + } + if (!(cdp = get_chunk_data(cfp->fp, cip))) + { + *status = CF_END_OF_FILE; + return NULL; + } + *status = CF_NORMAL; + return cdp; +} + +void nerv_chunk_file_close(ChunkFile *cfp) { + if (cfp->status != CF_CLOSED) + fclose(cfp->fp); + cfp->status = CF_CLOSED; +} + +void nerv_chunk_file_destroy(ChunkFile *cfp) { + ChunkInfo *i, *ni; + if (cfp->status != CF_CLOSED) fclose(cfp->fp); + for (i = cfp->info; i; i = ni) + { + ni = i->next; + free(i->metadata); + free(i); + } + free(cfp); +} + +void nerv_chunk_data_destroy(ChunkData *cdp) { + fclose(cdp->fp); + free(cdp->data); + free(cdp); +} + +const char *nerv_chunk_file_errstr(int status) { + switch (status) + { + case CF_INVALID_FORMAT: return "invalid format"; + case CF_END_OF_FILE: return "unexpected end of file"; + case CF_SECTION_OVERFLOW: return "section overflow"; + case CF_WRITE_ERROR: return "error while writing"; + case CF_ERR_OPEN_FILE: return "error while opening file"; + case CF_INVALID_OP: return "invalid operation"; + default: return "unknown"; + } + return NULL; +} |