/*= -*- c-basic-offset: 4; indent-tabs-mode: nil; -*- * * librsync -- the library for network deltas * * Copyright (C) 2000, 2001 by Martin Pool * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public License * as published by the Free Software Foundation; either version 2.1 of * the License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ /*= | This is Tranquility Base. */ /** \file patch.c * Apply a delta to an old file to generate a new file. */ #include #include #include #include #include "librsync.h" #include "job.h" #include "netint.h" #include "stream.h" #include "command.h" #include "prototab.h" #include "trace.h" static rs_result rs_patch_s_cmdbyte(rs_job_t *); static rs_result rs_patch_s_params(rs_job_t *); static rs_result rs_patch_s_run(rs_job_t *); static rs_result rs_patch_s_literal(rs_job_t *); static rs_result rs_patch_s_copy(rs_job_t *); static rs_result rs_patch_s_copying(rs_job_t *); /** State of trying to read the first byte of a command. Once we've taken that * in, we can know how much data to read to get the arguments. */ static rs_result rs_patch_s_cmdbyte(rs_job_t *job) { rs_result result; if ((result = rs_suck_byte(job, &job->op)) != RS_DONE) return result; job->cmd = &rs_prototab[job->op]; rs_trace("got command %#04x (%s), len_1=%d, len_2=%d", job->op, rs_op_kind_name(job->cmd->kind), job->cmd->len_1, job->cmd->len_2); if (job->cmd->len_1) job->statefn = rs_patch_s_params; else { job->param1 = job->cmd->immediate; job->statefn = rs_patch_s_run; } return RS_RUNNING; } /** Called after reading a command byte to pull in its parameters and then * setup to execute the command. */ static rs_result rs_patch_s_params(rs_job_t *job) { rs_result result; const size_t len = (size_t)(job->cmd->len_1 + job->cmd->len_2); void *p; assert(len); result = rs_scoop_readahead(job, len, &p); if (result != RS_DONE) return result; /* we now must have LEN bytes buffered */ result = rs_suck_netint(job, &job->param1, job->cmd->len_1); /* shouldn't fail, since we already checked */ assert(result == RS_DONE); if (job->cmd->len_2) { result = rs_suck_netint(job, &job->param2, job->cmd->len_2); assert(result == RS_DONE); } job->statefn = rs_patch_s_run; return RS_RUNNING; } /** Called when we've read in the whole command and we need to execute it. */ static rs_result rs_patch_s_run(rs_job_t *job) { rs_trace("running command %#04x", job->op); switch (job->cmd->kind) { case RS_KIND_LITERAL: job->statefn = rs_patch_s_literal; return RS_RUNNING; case RS_KIND_END: return RS_DONE; /* so we exit here; trying to continue causes an error */ case RS_KIND_COPY: job->statefn = rs_patch_s_copy; return RS_RUNNING; default: rs_error("bogus command %#04x", job->op); return RS_CORRUPT; } } /** Called when trying to copy through literal data. */ static rs_result rs_patch_s_literal(rs_job_t *job) { const rs_long_t len = job->param1; rs_stats_t *stats = &job->stats; rs_trace("LITERAL(length=" FMT_LONG ")", len); if (len <= 0 || len > SIZE_MAX) { rs_error("invalid length=" FMT_LONG " on LITERAL command", len); return RS_CORRUPT; } stats->lit_cmds++; stats->lit_bytes += len; stats->lit_cmdbytes += 1 + job->cmd->len_1; rs_tube_copy(job, (size_t)len); job->statefn = rs_patch_s_cmdbyte; return RS_RUNNING; } static rs_result rs_patch_s_copy(rs_job_t *job) { const rs_long_t pos = job->param1; const rs_long_t len = job->param2; rs_stats_t *stats = &job->stats; rs_trace("COPY(position=" FMT_LONG ", length=" FMT_LONG ")", pos, len); if (len <= 0) { rs_error("invalid length=" FMT_LONG " on COPY command", len); return RS_CORRUPT; } if (pos < 0) { rs_error("invalid position=" FMT_LONG " on COPY command", pos); return RS_CORRUPT; } stats->copy_cmds++; stats->copy_bytes += len; stats->copy_cmdbytes += 1 + job->cmd->len_1 + job->cmd->len_2; job->basis_pos = pos; job->basis_len = len; job->statefn = rs_patch_s_copying; return RS_RUNNING; } /** Called when we're executing a COPY command and waiting for all the data to * be retrieved from the callback. */ static rs_result rs_patch_s_copying(rs_job_t *job) { rs_result result; rs_buffers_t *buffs = job->stream; rs_long_t req = job->basis_len; size_t len = buffs->avail_out; void *ptr = buffs->next_out; /* We are blocked if there is no space left to copy into. */ if (!len) return RS_BLOCKED; /* Adjust request to min of amount requested and space available. */ if (len < req) req = (rs_long_t)len; rs_trace("copy " FMT_LONG " bytes from basis at offset " FMT_LONG "", req, job->basis_pos); len = (size_t)req; result = (job->copy_cb) (job->copy_arg, job->basis_pos, &len, &ptr); if (result != RS_DONE) { rs_trace("copy callback returned %s", rs_strerror(result)); return result; } rs_trace("got " FMT_SIZE " bytes back from basis callback", len); /* Actual copied length cannot be greater than requested length. */ assert(len <= req); /* Backwards-compatible defensively handle this for NDEBUG builds. */ if (len > req) { rs_warn("copy_cb() returned more than the requested length"); len = (size_t)req; } /* copy back to out buffer only if the callback has used its own buffer */ if (ptr != buffs->next_out) memcpy(buffs->next_out, ptr, len); /* Update buffs and copy for copied data. */ buffs->next_out += len; buffs->avail_out -= len; job->basis_pos += (rs_long_t)len; job->basis_len -= (rs_long_t)len; if (!job->basis_len) { /* Nothing left to copy, we are done! */ job->statefn = rs_patch_s_cmdbyte; } return RS_RUNNING; } /** Called while we're trying to read the header of the patch. */ static rs_result rs_patch_s_header(rs_job_t *job) { int v; rs_result result; if ((result = rs_suck_n4(job, &v)) != RS_DONE) return result; if (v != RS_DELTA_MAGIC) { rs_error("got magic number %#x rather than expected value %#x", v, RS_DELTA_MAGIC); return RS_BAD_MAGIC; } else rs_trace("got patch magic %#x", v); job->statefn = rs_patch_s_cmdbyte; return RS_RUNNING; } rs_job_t *rs_patch_begin(rs_copy_cb * copy_cb, void *copy_arg) { rs_job_t *job = rs_job_new("patch", rs_patch_s_header); job->copy_cb = copy_cb; job->copy_arg = copy_arg; rs_mdfour_begin(&job->output_md4); return job; }