X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=ovsdb%2Ffile.c;h=377ca280f5bb57a8966421ba9d9b8fdd8ed35571;hb=f0f54cb4dd1c4d890b6b4b9cd459c11fe880e88f;hp=4883d76f1b2144f78acc40ef17cad814c656f728;hpb=f85f8ebbfac946c19b3c6eb0f4170f579d0a4d25;p=openvswitch

diff --git a/ovsdb/file.c b/ovsdb/file.c
index 4883d76f..377ca280 100644
--- a/ovsdb/file.c
+++ b/ovsdb/file.c
@@ -18,343 +18,324 @@
 #include "file.h"
 
 #include <assert.h>
-#include <errno.h>
 #include <fcntl.h>
-#include <stdlib.h>
-#include <string.h>
-#include <unistd.h>
 
+#include "column.h"
+#include "log.h"
 #include "json.h"
-#include "lockfile.h"
+#include "ovsdb.h"
 #include "ovsdb-error.h"
-#include "sha1.h"
+#include "row.h"
+#include "table.h"
+#include "transaction.h"
+#include "uuid.h"
 #include "util.h"
 
 #define THIS_MODULE VLM_ovsdb_file
 #include "vlog.h"
 
-enum ovsdb_file_mode {
-    OVSDB_FILE_READ,
-    OVSDB_FILE_WRITE
-};
-
-struct ovsdb_file {
-    off_t offset;
-    char *name;
-    struct lockfile *lockfile;
-    FILE *stream;
-    struct ovsdb_error *read_error;
-    struct ovsdb_error *write_error;
-    enum ovsdb_file_mode mode;
-};
+static struct ovsdb_error *ovsdb_file_txn_from_json(struct ovsdb *,
+                                                    const struct json *,
+                                                    struct ovsdb_txn **);
+static void ovsdb_file_replica_create(struct ovsdb *, struct ovsdb_log *);
 
 struct ovsdb_error *
-ovsdb_file_open(const char *name, int flags, struct ovsdb_file **filep)
+ovsdb_file_open(const char *file_name, bool read_only, struct ovsdb **dbp)
 {
-    struct lockfile *lockfile;
+    struct ovsdb_schema *schema;
     struct ovsdb_error *error;
-    struct ovsdb_file *file;
-    struct stat s;
-    FILE *stream;
-    int accmode;
-    int fd;
-
-    *filep = NULL;
-
-    accmode = flags & O_ACCMODE;
-    if (accmode == O_RDWR || accmode == O_WRONLY) {
-        int retval = lockfile_lock(name, 0, &lockfile);
-        if (retval) {
-            error = ovsdb_io_error(retval, "%s: failed to lock lockfile",
-                                   name);
-            goto error;
-        }
-    } else {
-        lockfile = NULL;
+    struct ovsdb_log *log;
+    struct json *json;
+    struct ovsdb *db;
+
+    error = ovsdb_log_open(file_name, read_only ? O_RDONLY : O_RDWR, &log);
+    if (error) {
+        return error;
     }
 
-    fd = open(name, flags, 0666);
-    if (fd < 0) {
-        const char *op = flags & O_CREAT && flags & O_EXCL ? "create" : "open";
-        error = ovsdb_io_error(errno, "%s: %s failed", op, name);
-        goto error_unlock;
+    error = ovsdb_log_read(log, &json);
+    if (error) {
+        return error;
+    } else if (!json) {
+        return ovsdb_io_error(EOF, "%s: database file contains no schema",
+                              file_name);
     }
 
-    if (!fstat(fd, &s) && s.st_size == 0) {
-        /* It's (probably) a new file so fsync() its parent directory to ensure
-         * that its directory entry is committed to disk. */
-        char *dir = dir_name(name);
-        int dirfd = open(dir, O_RDONLY);
-        if (dirfd >= 0) {
-            if (fsync(dirfd) && errno != EINVAL) {
-                VLOG_ERR("%s: fsync failed (%s)", dir, strerror(errno));
-            }
-            close(dirfd);
-        } else {
-            VLOG_ERR("%s: open failed (%s)", dir, strerror(errno));
+    error = ovsdb_schema_from_json(json, &schema);
+    if (error) {
+        json_destroy(json);
+        return ovsdb_wrap_error(error,
+                                "failed to parse \"%s\" as ovsdb schema",
+                                file_name);
+    }
+    json_destroy(json);
+
+    db = ovsdb_create(schema);
+    while ((error = ovsdb_log_read(log, &json)) == NULL && json) {
+        struct ovsdb_txn *txn;
+
+        error = ovsdb_file_txn_from_json(db, json, &txn);
+        json_destroy(json);
+        if (error) {
+            break;
         }
-        free(dir);
+
+        ovsdb_txn_commit(txn, false);
     }
+    if (error) {
+        char *msg = ovsdb_error_to_string(error);
+        VLOG_WARN("%s", msg);
+        free(msg);
 
-    stream = fdopen(fd, (accmode == O_RDONLY ? "rb"
-                         : accmode == O_WRONLY ? "wb"
-                         : "w+b"));
-    if (!stream) {
-        error = ovsdb_io_error(errno, "%s: fdopen failed", name);
-        goto error_close;
+        ovsdb_error_destroy(error);
     }
 
-    file = xmalloc(sizeof *file);
-    file->name = xstrdup(name);
-    file->lockfile = lockfile;
-    file->stream = stream;
-    file->offset = 0;
-    file->read_error = NULL;
-    file->write_error = NULL;
-    file->mode = OVSDB_FILE_READ;
-    *filep = file;
-    return NULL;
+    if (!read_only) {
+        ovsdb_file_replica_create(db, log);
+    } else {
+        ovsdb_log_close(log);
+    }
 
-error_close:
-    close(fd);
-error_unlock:
-    lockfile_unlock(lockfile);
-error:
-    return error;
+    *dbp = db;
+    return NULL;
 }
 
-void
-ovsdb_file_close(struct ovsdb_file *file)
+static struct ovsdb_error *
+ovsdb_file_txn_row_from_json(struct ovsdb_txn *txn, struct ovsdb_table *table,
+                             const struct uuid *row_uuid, struct json *json)
 {
-    if (file) {
-        free(file->name);
-        fclose(file->stream);
-        lockfile_unlock(file->lockfile);
-        ovsdb_error_destroy(file->read_error);
-        ovsdb_error_destroy(file->write_error);
-        free(file);
+    const struct ovsdb_row *row = ovsdb_table_get_row(table, row_uuid);
+    if (json->type == JSON_NULL) {
+        if (!row) {
+            return ovsdb_syntax_error(NULL, NULL, "transaction deletes "
+                                      "row "UUID_FMT" that does not exist",
+                                      UUID_ARGS(row_uuid));
+        }
+        ovsdb_txn_row_delete(txn, row);
+        return NULL;
+    } else if (row) {
+        return ovsdb_row_from_json(ovsdb_txn_row_modify(txn, row),
+                                   json, NULL, NULL);
+    } else {
+        struct ovsdb_error *error;
+        struct ovsdb_row *new;
+
+        new = ovsdb_row_create(table);
+        *ovsdb_row_get_uuid_rw(new) = *row_uuid;
+        error = ovsdb_row_from_json(new, json, NULL, NULL);
+        if (error) {
+            ovsdb_row_destroy(new);
+        }
+
+        ovsdb_txn_row_insert(txn, new);
+
+        return error;
     }
 }
 
-static const char magic[] = "OVSDB JSON ";
-
-static bool
-parse_header(char *header, unsigned long int *length,
-             uint8_t sha1[SHA1_DIGEST_SIZE])
+static struct ovsdb_error *
+ovsdb_file_txn_table_from_json(struct ovsdb_txn *txn,
+                               struct ovsdb_table *table, struct json *json)
 {
-    char *p;
+    struct shash_node *node;
 
-    /* 'header' must consist of a magic string... */
-    if (strncmp(header, magic, strlen(magic))) {
-        return false;
+    if (json->type != JSON_OBJECT) {
+        return ovsdb_syntax_error(json, NULL, "object expected");
     }
 
-    /* ...followed by a length in bytes... */
-    *length = strtoul(header + strlen(magic), &p, 10);
-    if (!*length || *length == ULONG_MAX || *p != ' ') {
-        return false;
+    SHASH_FOR_EACH (node, json->u.object) {
+        const char *uuid_string = node->name;
+        struct json *txn_row_json = node->data;
+        struct ovsdb_error *error;
+        struct uuid row_uuid;
+
+        if (!uuid_from_string(&row_uuid, uuid_string)) {
+            return ovsdb_syntax_error(json, NULL, "\"%s\" is not a valid UUID",
+                                      uuid_string);
+        }
+
+        error = ovsdb_file_txn_row_from_json(txn, table, &row_uuid,
+                                             txn_row_json);
+        if (error) {
+            return error;
+        }
     }
-    p++;
 
-    /* ...followed by a SHA-1 hash... */
-    if (!sha1_from_hex(sha1, p)) {
-        return false;
+    return NULL;
+}
+
+static struct ovsdb_error *
+ovsdb_file_txn_from_json(struct ovsdb *db, const struct json *json,
+                         struct ovsdb_txn **txnp)
+{
+    struct ovsdb_error *error;
+    struct shash_node *node;
+    struct ovsdb_txn *txn;
+
+    *txnp = NULL;
+    if (json->type != JSON_OBJECT) {
+        return ovsdb_syntax_error(json, NULL, "object expected");
     }
-    p += SHA1_HEX_DIGEST_LEN;
 
-    /* ...and ended by a new-line. */
-    if (*p != '\n') {
-        return false;
+    txn = ovsdb_txn_create(db);
+    SHASH_FOR_EACH (node, json->u.object) {
+        const char *table_name = node->name;
+        struct json *txn_table_json = node->data;
+        struct ovsdb_table *table;
+
+        table = shash_find_data(&db->tables, table_name);
+        if (!table) {
+            error = ovsdb_syntax_error(json, "unknown table",
+                                       "No table named %s.", table_name);
+            goto error;
+        }
+
+        error = ovsdb_file_txn_table_from_json(txn, table, txn_table_json);
+        if (error) {
+            goto error;
+        }
     }
+    *txnp = txn;
+    return NULL;
 
-    return true;
+error:
+    ovsdb_txn_abort(txn);
+    return error;
 }
+
+/* Replica implementation. */
 
-struct ovsdb_file_read_cbdata {
-    char input[4096];
-    struct ovsdb_file *file;
-    int error;
-    unsigned long length;
+struct ovsdb_file_replica {
+    struct ovsdb_replica replica;
+    struct ovsdb_log *log;
 };
 
-static struct ovsdb_error *
-parse_body(struct ovsdb_file *file, off_t offset, unsigned long int length,
-           uint8_t sha1[SHA1_DIGEST_SIZE], struct json **jsonp)
+static const struct ovsdb_replica_class ovsdb_file_replica_class;
+
+static void
+ovsdb_file_replica_create(struct ovsdb *db, struct ovsdb_log *log)
 {
-    unsigned long int bytes_left;
-    struct json_parser *parser;
-    struct sha1_ctx ctx;
-
-    sha1_init(&ctx);
-    parser = json_parser_create(JSPF_TRAILER);
-
-    bytes_left = length;
-    while (length > 0) {
-        char input[BUFSIZ];
-        int chunk;
-
-        chunk = MIN(length, sizeof input);
-        if (fread(input, 1, chunk, file->stream) != chunk) {
-            json_parser_abort(parser);
-            return ovsdb_io_error(ferror(file->stream) ? errno : EOF,
-                                  "%s: error reading %lu bytes "
-                                  "starting at offset %lld", file->name,
-                                  length, (long long int) offset);
-        }
-        sha1_update(&ctx, input, chunk);
-        json_parser_feed(parser, input, chunk);
-        length -= chunk;
-    }
+    struct ovsdb_file_replica *r = xmalloc(sizeof *r);
+    ovsdb_replica_init(&r->replica, &ovsdb_file_replica_class);
+    r->log = log;
+    ovsdb_add_replica(db, &r->replica);
 
-    sha1_final(&ctx, sha1);
-    *jsonp = json_parser_finish(parser);
-    return NULL;
 }
 
-struct ovsdb_error *
-ovsdb_file_read(struct ovsdb_file *file, struct json **jsonp)
+static struct ovsdb_file_replica *
+ovsdb_file_replica_cast(struct ovsdb_replica *replica)
 {
-    uint8_t expected_sha1[SHA1_DIGEST_SIZE];
-    uint8_t actual_sha1[SHA1_DIGEST_SIZE];
-    struct ovsdb_error *error;
-    off_t data_offset;
-    unsigned long data_length;
-    struct json *json;
-    char header[128];
+    assert(replica->class == &ovsdb_file_replica_class);
+    return CONTAINER_OF(replica, struct ovsdb_file_replica, replica);
+}
 
-    *jsonp = json = NULL;
+struct ovsdb_file_replica_aux {
+    struct json *json;          /* JSON for the whole transaction. */
+    struct json *table_json;    /* JSON for 'table''s transaction. */
+    struct ovsdb_table *table;  /* Table described in 'table_json'.  */
+};
 
-    if (file->read_error) {
-        return ovsdb_error_clone(file->read_error);
-    } else if (file->mode == OVSDB_FILE_WRITE) {
-        return OVSDB_BUG("reading file in write mode");
-    }
+static bool
+ovsdb_file_replica_change_cb(const struct ovsdb_row *old,
+                             const struct ovsdb_row *new,
+                             void *aux_)
+{
+    struct ovsdb_file_replica_aux *aux = aux_;
+    struct json *row;
 
-    if (!fgets(header, sizeof header, file->stream)) {
-        if (feof(file->stream)) {
-            error = NULL;
-        } else {
-            error = ovsdb_io_error(errno, "%s: read failed", file->name);
+    if (!new) {
+        row = json_null_create();
+    } else {
+        struct shash_node *node;
+
+        row = NULL;
+        SHASH_FOR_EACH (node, &new->table->schema->columns) {
+            const struct ovsdb_column *column = node->data;
+            const struct ovsdb_type *type = &column->type;
+            unsigned int idx = column->index;
+
+            if (idx != OVSDB_COL_UUID && column->persistent
+                && (!old || !ovsdb_datum_equals(&old->fields[idx],
+                                                &new->fields[idx], type)))
+            {
+                if (!row) {
+                    row = json_object_create();
+                }
+                json_object_put(row, column->name,
+                                ovsdb_datum_to_json(&new->fields[idx], type));
+            }
         }
-        goto error;
     }
 
-    if (!parse_header(header, &data_length, expected_sha1)) {
-        error = ovsdb_syntax_error(NULL, NULL, "%s: parse error at offset "
-                                   "%lld in header line \"%.*s\"",
-                                   file->name, (long long int) file->offset,
-                                   (int) strcspn(header, "\n"), header);
-        goto error;
-    }
+    if (row) {
+        struct ovsdb_table *table = new ? new->table : old->table;
+        char uuid[UUID_LEN + 1];
 
-    data_offset = file->offset + strlen(header);
-    error = parse_body(file, data_offset, data_length, actual_sha1, &json);
-    if (error) {
-        goto error;
-    }
+        if (table != aux->table) {
+            /* Create JSON object for transaction overall. */
+            if (!aux->json) {
+                aux->json = json_object_create();
+            }
 
-    if (memcmp(expected_sha1, actual_sha1, SHA1_DIGEST_SIZE)) {
-        error = ovsdb_syntax_error(NULL, NULL, "%s: %lu bytes starting at "
-                                   "offset %lld have SHA-1 hash "SHA1_FMT" "
-                                   "but should have hash "SHA1_FMT,
-                                   file->name, data_length,
-                                   (long long int) data_offset,
-                                   SHA1_ARGS(actual_sha1),
-                                   SHA1_ARGS(expected_sha1));
-        goto error;
-    }
+            /* Create JSON object for transaction on this table. */
+            aux->table_json = json_object_create();
+            aux->table = table;
+            json_object_put(aux->json, table->schema->name, aux->table_json);
+        }
 
-    if (json->type == JSON_STRING) {
-        error = ovsdb_syntax_error(NULL, NULL, "%s: %lu bytes starting at "
-                                   "offset %lld are not valid JSON (%s)",
-                                   file->name, data_length,
-                                   (long long int) data_offset,
-                                   json->u.string);
-        goto error;
+        /* Add row to transaction for this table. */
+        snprintf(uuid, sizeof uuid,
+                 UUID_FMT, UUID_ARGS(ovsdb_row_get_uuid(new ? new : old)));
+        json_object_put(aux->table_json, uuid, row);
     }
 
-    file->offset = data_offset + data_length;
-    *jsonp = json;
-    return 0;
-
-error:
-    file->read_error = ovsdb_error_clone(error);
-    json_destroy(json);
-    return error;
+    return true;
 }
 
-struct ovsdb_error *
-ovsdb_file_write(struct ovsdb_file *file, struct json *json)
+static struct ovsdb_error *
+ovsdb_file_replica_commit(struct ovsdb_replica *r_,
+                          const struct ovsdb_txn *txn, bool durable)
 {
-    uint8_t sha1[SHA1_DIGEST_SIZE];
+    struct ovsdb_file_replica *r = ovsdb_file_replica_cast(r_);
+    struct ovsdb_file_replica_aux aux;
     struct ovsdb_error *error;
-    char *json_string;
-    char header[128];
-    size_t length;
-
-    json_string = NULL;
-
-    if (file->write_error) {
-        return ovsdb_error_clone(file->write_error);
-    } else if (file->mode == OVSDB_FILE_READ) {
-        file->mode = OVSDB_FILE_WRITE;
-        if (fseeko(file->stream, file->offset, SEEK_SET)) {
-            error = ovsdb_io_error(errno, "%s: cannot seek to offset %lld",
-                                   file->name, (long long int) file->offset);
-            goto error;
-        }
-        if (ftruncate(fileno(file->stream), file->offset)) {
-            error = ovsdb_io_error(errno, "%s: cannot truncate to length %lld",
-                                   file->name, (long long int) file->offset);
-            goto error;
-        }
-    }
 
-    if (json->type != JSON_OBJECT && json->type != JSON_ARRAY) {
-        error = OVSDB_BUG("bad JSON type");
-        goto error;
+    aux.json = NULL;
+    aux.table_json = NULL;
+    aux.table = NULL;
+    ovsdb_txn_for_each_change(txn, ovsdb_file_replica_change_cb, &aux);
+
+    if (!aux.json) {
+        /* Nothing to commit. */
+        return NULL;
     }
 
-    /* Compose content.  Add a new-line (replacing the null terminator) to make
-     * the file easier to read, even though it has no semantic value.  */
-    json_string = json_to_string(json, 0);
-    length = strlen(json_string) + 1;
-    json_string[length - 1] = '\n';
-
-    /* Compose header. */
-    sha1_bytes(json_string, length, sha1);
-    snprintf(header, sizeof header, "%s%zu "SHA1_FMT"\n",
-             magic, length, SHA1_ARGS(sha1));
-
-    /* Write. */
-    if (fwrite(header, strlen(header), 1, file->stream) != 1
-        || fwrite(json_string, length, 1, file->stream) != 1
-        || fflush(file->stream))
-    {
-        error = ovsdb_io_error(errno, "%s: write failed", file->name);
-
-        /* Remove any partially written data, ignoring errors since there is
-         * nothing further we can do. */
-        ftruncate(fileno(file->stream), file->offset);
-
-        goto error;
+    error = ovsdb_log_write(r->log, aux.json);
+    json_destroy(aux.json);
+    if (error) {
+        return ovsdb_wrap_error(error, "writing transaction failed");
     }
 
-    file->offset += strlen(header) + length;
-    free(json_string);
-    return 0;
+    if (durable) {
+        error = ovsdb_log_commit(r->log);
+        if (error) {
+            return ovsdb_wrap_error(error, "committing transaction failed");
+        }
+    }
 
-error:
-    file->write_error = ovsdb_error_clone(error);
-    free(json_string);
-    return error;
+    return NULL;
 }
 
-struct ovsdb_error *
-ovsdb_file_commit(struct ovsdb_file *file)
+static void
+ovsdb_file_replica_destroy(struct ovsdb_replica *r_)
 {
-    if (fsync(fileno(file->stream))) {
-        return ovsdb_io_error(errno, "%s: fsync failed", file->name);
-    }
-    return 0;
+    struct ovsdb_file_replica *r = ovsdb_file_replica_cast(r_);
+
+    ovsdb_log_close(r->log);
+    free(r);
 }
+
+static const struct ovsdb_replica_class ovsdb_file_replica_class = {
+    ovsdb_file_replica_commit,
+    ovsdb_file_replica_destroy
+};