diff options
Diffstat (limited to 'src/cache.c')
| -rw-r--r-- | src/cache.c | 229 |
1 files changed, 229 insertions, 0 deletions
diff --git a/src/cache.c b/src/cache.c new file mode 100644 index 0000000..860b4fb --- /dev/null +++ b/src/cache.c @@ -0,0 +1,229 @@ +#include <db.h> +#include <stdlib.h> +#include <assert.h> +#include <time.h> +#include <string.h> +#include <unistd.h> +#include <fcntl.h> +#include <errno.h> +#include <sys/types.h> +#include <sys/stat.h> + +#include "cache.h" +#include "md5util.h" + +struct syrep_cache_key { + uint64_t dev; + uint64_t inode; + uint32_t date; + uint64_t size; +}; + +struct syrep_cache_data { + uint8_t digest[16]; + uint32_t timestamp; +}; + +struct syrep_md_cache { + DB* db; + uint32_t timestamp; + int ro; +}; + +struct syrep_md_cache* md_cache_open(const char* fn, int ro) { + struct syrep_md_cache *c = NULL; + int ret; + + assert(fn); + + if (!(c = malloc(sizeof(struct syrep_md_cache)))) + goto fail; + + c->timestamp = time(NULL); + c->ro = ro; + + if ((ret = db_create(&c->db, NULL, 0))) { + fprintf(stderr, "db_create: %s\n", db_strerror(ret)); + goto fail; + } + + if ((ret = c->db->open(c->db, NULL, fn, NULL, DB_BTREE, ro ? DB_RDONLY : DB_CREATE, 0664))) { + c->db->err(c->db, ret, "open(%s)", fn); + goto fail; + } + + return c; + +fail: + + if (c) { + if (c->db) + c->db->close(c->db, 0); + + free(c); + } + + return NULL; +} + +void md_cache_close(struct syrep_md_cache *c) { + assert(c); + + if (c->db) + c->db->close(c->db, 0); + + free(c); +} + +static int get(struct syrep_md_cache *c, const struct syrep_cache_key *k, uint8_t digest[16]) { + int ret; + DBT key, data; + + assert(c && c->db && k); + + memset(&key, 0, sizeof(key)); + memset(&data, 0, sizeof(data)); + + key.data = (void*) k; + key.size = sizeof(struct syrep_cache_key); + + if ((ret = c->db->get(c->db, NULL, &key, &data, 0)) != 0) { + if (ret == DB_NOTFOUND) { + //fprintf(stderr, "Cache MISS!\n"); + return 0; + } + + c->db->err(c->db, ret, "cache::get"); + return -1; + } + + //fprintf(stderr, "Cache HIT\n"); + + assert(data.data); + memcpy(digest, &((struct syrep_cache_data*) data.data)->digest, 16); + + return 1; +} + +static int put(struct syrep_md_cache *c, const struct syrep_cache_key *k, const uint8_t digest[16], uint32_t timestamp) { + int ret; + DBT key, data; + struct syrep_cache_data d; + + assert(c && c->db && k); + + memset(&key, 0, sizeof(key)); + key.data = (void*) k; + key.size = sizeof(struct syrep_cache_key); + + memcpy(d.digest, digest, 16); + d.timestamp = timestamp; + + memset(&data, 0, sizeof(data)); + data.data = &d; + data.size = sizeof(struct syrep_cache_data); + + if ((ret = c->db->put(c->db, NULL, &key, &data, 0)) != 0) { + c->db->err(c->db, ret, "cache::put"); + return -1; + } + + return 0; +} + +int md_cache_get(struct syrep_md_cache *c, const char *path, uint8_t digest[16]) { + struct syrep_cache_key k; + int r = -1, fd = -1, j; + struct stat st; + + if ((fd = open(path, O_RDONLY)) < 0) { + fprintf(stderr, "open(%s): %s\n", path, strerror(errno)); + goto finish; + } + + if (fstat(fd, &st) < 0) { + fprintf(stderr, "fstat(%s): %s\n", path, strerror(errno)); + goto finish; + } + + if (!S_ISREG(st.st_mode)) { + fprintf(stderr, "<%s> not a regular file: %s\n", path, strerror(errno)); + goto finish; + } + + memset(&k, 0, sizeof(k)); + k.dev = (uint64_t) st.st_dev; + k.inode = (uint64_t) st.st_ino; + k.date = (uint32_t) st.st_mtime; + k.size = (uint64_t) st.st_size; + + if (!c) + j = 0; + else + if ((j = get(c, &k, digest)) < 0) + goto finish; + + + if (!j) + if (fdmd5(fd, st.st_size, digest) < 0) + goto finish; + + if (c && !c->ro) + put(c, &k, digest, c->timestamp); + + r = 0; + +finish: + + if (fd >= 0) + close(fd); + + return r; +} + +int md_cache_vacuum(struct syrep_md_cache*c) { + int r = -1, ret; + DBC *cursor; + DBT key, data; + int ndel = 0, ntotal = 0; + + if (c->ro) + return 0; + + assert(c && c->db); + + if ((ret = c->db->cursor(c->db, NULL, &cursor, 0)) != 0) { + c->db->err(c->db, ret, "cache::vacuum"); + return -1; + } + + memset(&key, 0, sizeof(key)); + memset(&data, 0, sizeof(data)); + + while ((ret = cursor->c_get(cursor, &key, &data, DB_NEXT)) == 0) { + struct syrep_cache_data *d; + + ntotal++; + d = (struct syrep_cache_data*) data.data; + assert(d); + if (d->timestamp < c->timestamp) { + cursor->c_del(cursor, 0); + ndel++; + } + } + + if (ret != DB_NOTFOUND) { + c->db->err(c->db, ret, "cache::vacuum()"); + goto finish; + } + + /*fprintf(stderr, "Cache vacuum successfully completed, %i of %i entries deleted.\n", ndel, ntotal);*/ + + r = 0; + +finish: + + cursor->c_close(cursor); + + return r; +} |