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#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <ftw.h>
#include <sha1.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#define MAX_DEPTH 256
#define CVN_DIR ".cvn"
#define INDEX_FILE "index"
#define HASH_LEN SHA1_DIGEST_LENGTH
#define HASH_INPUT_LEN 4096
#define MALLOC(s) _xmalloc((s), __FILE__, __LINE__)
#define REALLOC(p, s) _xrealloc((p), (s), __FILE__, __LINE__)
static inline void init(int argc, char *argv[]);
static inline void status(int argc, char *argv[]);
static inline void update_index(void);
static inline int ignore(const char *path);
static inline void *_xmalloc(size_t s, const char *file, int line);
static inline void *_xrealloc(void *ptr, size_t s, const char *file, int line);
struct command {
char *name;
void (*func)(int argc, char *argv[]);
};
struct command cmd[] = {
{"init", init},
{"status", status},
{NULL, NULL}
};
int main(int argc, char *argv[])
{
int i;
if (argc < 2)
errx(1, "Usage: %s <command> [<args>]", argv[0]);
for (i = 0; cmd[i].name != NULL; i++) {
if (strcmp(argv[1], cmd[i].name) == 0) {
cmd[i].func(argc - 1, argv + 1);
return 0;
}
}
return 0;
}
static inline void init(int argc, char *argv[])
{
char *branch;
int opt, repo_fd, idx_fd;
optind = 1;
while ((opt = getopt(argc, argv, "b:")) != -1) {
switch (opt) {
case 'b':
branch = optarg;
break;
default:
break;
}
}
if (mkdir(CVN_DIR, 0755) == -1) {
if (errno != EEXIST)
err(1, "Failed to create repository");
}
if ((repo_fd = open(CVN_DIR, O_RDONLY | O_DIRECTORY)) == -1)
err(1, "Failed to open repository");
if ((idx_fd = openat(repo_fd, INDEX_FILE,
O_WRONLY | O_CREAT | O_EXCL, 0644)) == -1) {
if (errno != EEXIST) {
close(repo_fd);
err(1, "Failed to create index");
}
} else
close(idx_fd);
close(repo_fd);
printf("Initialized repository in %s\n", CVN_DIR);
}
static inline void status(int argc, char *argv[])
{
update_index();
}
static char hash_input[HASH_INPUT_LEN];
static uint8_t *hash_at_level[MAX_DEPTH] = {0};
static inline void print_hash(const uint8_t hash[HASH_LEN],
const char *path)
{
printf("0x");
for (int i = 0; i < HASH_LEN; i++)
printf("%02x", hash[i]);
printf(": %s\n", path);
}
void update_hash_at(size_t level, const uint8_t *hash)
{
SHA1_CTX ctx;
if (level >= 0) {
if (hash_at_level[level]) {
SHA1Init(&ctx);
SHA1Update(&ctx, hash_at_level[level], HASH_LEN);
SHA1Update(&ctx, hash, HASH_LEN);
SHA1Final(hash_at_level[level], &ctx);
} else {
hash_at_level[level] = MALLOC(sizeof(uint8_t) * HASH_LEN);
memcpy(hash_at_level[level], hash, HASH_LEN);
}
}
}
void hash_file(const char *path, uint8_t *hash)
{
int fd;
SHA1_CTX ctx;
ssize_t bytes_read;
if ((fd = open(path, O_RDONLY)) == -1)
err(1, "Failed to open %s", path);
SHA1Init(&ctx);
while ((bytes_read = read(fd, hash_input, sizeof(hash_input))) > 0)
SHA1Update(&ctx, hash_input, (size_t)bytes_read);
if (bytes_read == -1)
err(1, "Failed to read %s", path);
SHA1Final(hash, &ctx);
close(fd);
}
void hash_path(const char *path, uint8_t *hash)
{
SHA1_CTX ctx;
ssize_t lnk_len;
lnk_len = readlink(path, hash_input, HASH_INPUT_LEN - 1);
if (lnk_len == -1)
err(1, "readlink failed for %s", path);
hash_input[lnk_len] = '\0';
SHA1Init(&ctx);
SHA1Update(&ctx, hash_input, lnk_len);
SHA1Final(hash, &ctx);
}
static inline void hash_dir(size_t level, uint8_t *hash)
{
memcpy(hash, hash_at_level[level], HASH_LEN);
free(hash_at_level[level]);
hash_at_level[level] = NULL;
}
int compute_hash(const char * path, const struct stat *st,
int tflag, struct FTW *ftwbuf)
{
int level;
mode_t mode;
unsigned char hash[HASH_LEN];
const char *file_name = path + ftwbuf->base;
if (ignore(file_name))
return 0;
mode = st->st_mode;
level = ftwbuf->level;
if (tflag == FTW_F) {
if (S_ISREG(mode))
hash_file(path, hash);
else if (S_ISLNK(mode))
hash_path(path, hash);
update_hash_at(level - 1, hash);
} else if (tflag == FTW_DP) {
hash_dir(level, hash);
update_hash_at(level - 1, hash);
}
print_hash(hash, path);
return 0;
}
static inline void update_index(void)
{
if (nftw(".", compute_hash, MAX_DEPTH, FTW_DEPTH | FTW_PHYS) == -1)
err(1, "nftw");
}
static inline int ignore(const char *path)
{
return strcmp(path, CVN_DIR) == 0;
}
static inline void *_xmalloc(size_t s, const char *file, int line)
{
void *p;
if (!(p = malloc(s)))
err(1, "%s:%d: malloc", file, line);
return p;
}
static inline void *_xrealloc(void *ptr, size_t s,
const char *file, int line)
{
void *p;
if (!(p = realloc(ptr, s)))
err(1, "%s:%d: realloc", file, line);
return p;
}
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